bluuebunny/crossref_metadata_2025 huggingface dataset:
Janus nanocarrier powered by bi-enzymatic cascade system for smart delivery
Authors: Jimenez-Falcao Sandra , Joga Natalia , García-Fernández Alba , Llopis Lorente Antoni , Torres Daniel , de Luis Beatriz , Sancenón Félix , Martínez-Ruiz Paloma , Martínez-Máñez Ramón , Villalonga Reynaldo
Published: July 2019

A novel integrated Janus nanodevice with bi-enzymatic cascade control successfully employed for on-command release of doxorubicin is reported here.
Mechanochemical engineering of 2D materials for multiscale biointerfaces
Authors: Machnicki Catherine E. , Fu Fanfan , Jing Lin , Chen Po-Yen , Wong Ian Y.
Published: July 2019

Atomically thin nanomaterials that are wrinkled or crumpled represent a unique paradigm for interfacing with biological systems due to their mechanical flexibility, exceptional interfacial area, and ease of chemical functionalization.
The programmed site-specific delivery of the angiostatin sunitinib and chemotherapeutic paclitaxel for highly efficient tumor treatment
Authors: He Jin , Xiao Hong , Li Bo , Peng Yuan , Li Xiaoxia , Wang Yong , Adamus Grazyna , Kowalczuk Marek , Shuai Xintao
Published: July 2019

A pH and MMP-2 dual sensitive polymeric micelle was synthesized for programmed site-specific delivery of angiostatin sunitinib and chemotherapeutic paclitaxel.
Diselenium-containing ultrathin polymer nanocapsules for highly efficient targeted drug delivery and combined anticancer effect
Authors: Fu Shuang , Li Fei , Zang Mingsong , Zhang Zherui , Ji Yuancheng , Yu Xiaoxuan , Luo Quan , Guan Shuwen , Xu Jiayun , Liu Junqiu
Published: July 2019

A new highly efficient targeting drug delivery vehicle based on diselenium-containing ultrathin polymer nanocapsules was designed and prepared.
Chemical phase segregation during the crystallization of Ge-rich GeSbTe alloys
Authors: Agati Marta , Vallet Maxime , Joulié Sébastien , Benoit Daniel , Claverie Alain
Published: July 2019

Crystallization of Ge-rich GST leads to phase separation, a characteristic which explains their superior properties for electronic memory devices
Correlated lateral and vertical transport of large-scale majority carrier graphene–insulator–silicon photodiodes
Authors: Park Hong-Ki , Cho Yeonsoo , Kim Myeongseop , Choi Jaewu
Published: July 2019

Mapped photo-responsivity of a graphene–insulator–silicon photodetector having a double-electrode configuration illuminated with 10 μW of optical power and at an applied reverse bias voltage of −5 V.
Observation of superconductivity in pressurized 2M WSe2 crystals
Authors: Fang Yuqiang , Dong Qing , Pan Jie , Liu Hanyu , Liu Pan , Sun Yiyang , Li Quanjun , Zhao Wei , Liu Bingbing , Huang Fuqiang
Published: July 2019

In this communication, we report a new-phase 2M WSe2 with a monoclinic space group C2/m. 2M WSe2 presents a metallic behavior under ambient pressure and shows superconducting transition with a maximum Tc of 7.3 K at 10.7 GPa.
An optical perspective on the thermal-activated ionic migration state and ionic jumping distance in glass
Authors: Zhu Jiaxi , He Qian , Kuang Xiaojun , Ye Shi
Published: July 2019

The research unravels the upconversion luminescence behaviours of Er3+ in the dynamic ionic migration state with a jumping distance of 1.8 Å in Na+-conducting silicate glass.
Investigating wind turbine dynamic transient loads using contactless shaft torque measurements
Authors: Zappalá Donatella , Crabtree Christopher J. , Hogg Simon
Published: July 2019

The wind industry is showing increasing awareness about the importance of long‐term direct shaft mechanical torque measurements to fully understand wind turbine (WT) dynamics, adopt proactive solutions for extreme load mitigation and enhance condition monitoring (CM) capabilities. Although torsional effects are important, torque measurement on such large, inaccessible machines is practically and logistically difficult, mainly because of the costly and intrusive specialised equipment currently available. This study details an experimental set‐up for the investigation of shaft dynamic transient load and speed measurements through a contactless, low‐cost torque meter. Results are obtained over a range of applied loads and compared with reference measurements from an in‐line, invasive torque transducer. Average torque and speed root‐mean‐square error values of 0.53 Nm and 0.35 rpm, respectively, indicate good accuracy of the proposed contactless torque meter. Its implementation in the field would allow direct, cheap, real‐time measurements of WT drive train loads for performance monitoring, control and CM purposes.
The diagnostic potential of the weak field approximation for investigating the quiet Sun magnetism: the Si I 10 827 Å line
Authors: Shchukina N. G. , Trujillo Bueno J.
Published: July 2019

Aims. We aim to investigate the validity of the weak field approximation (WFA) for determining magnetic fields in quiet regions of the solar photosphere using the polarization caused by the Zeeman effect in the Si I10 827 Å line.

Methods. We solved the NLTE line formation problem by means of multilevel radiative transfer calculations in a three-dimensional (3D) snapshot model taken from a state-of-the-art magneto-convection simulation of the small-scale magnetic activity in the quiet solar photosphere. The 3D model used is characterized by a surface mean magnetic field strength of about 170 G. The calculated Stokes profiles were degraded because of the atmospheric turbulence of Earth and light diffraction by the telescope aperture. We apply the WFA to the StokesI,Q,U,Vprofiles calculated for different seeing conditions and for the apertures of the VTT, GREGOR, EST and DKIST telescopes. We compare the inferred longitudinal and transverse components of the magnetic field with the original vertical and horizontal fields of the 3D model.

Results. We find that with a spatial resolution significantly better than 0.5″ the surface maps of the magnetic field inferred from the Stokes profiles of the Si I10 827 Å line applying the WFA are close to the magnetic field of the model on the corrugated surface, corresponding to line optical depth unity at Δλ ≈ 0.1 Å for a disk-center line of sight. The correlation between them is relatively high, except that the inferred longitudinal and transverse components of the magnetic field turn out to be lower than in the 3D model.

Conclusions. The use of the WFA for interpreting high-spatial-resolution spectropolarimetric observations of the Si I10 827 Å line obtained with telescopes like GREGOR, EST, and DKIST allows the longitudinal and transverse components of the magnetic field to be retrieved with reasonable precision over the whole quiet solar photosphere, the result being worse for telescopes of lower aperture.
Characterization of inclusions in axle steel by ingot casting
Authors: Zhou Qinghai , Zhang Jiongming , Yin Yanbin , Zhai Mingzhi
Published: July 2019

The composition, size distribution and number density of inclusions in the rolled billet of bottom-teemed axle steel have been investigated through the inclusion automatic analysis system (INCAFeature, Oxford Instruments). Additionally, the thermodynamics calculation of sulfide precipitation during the solidification and rolling processes has been carried out. Seven types of inclusions are found in rolled billets, which are almost originated from the refined molten steel. However, re-oxidation, sulfide precipitation and mold powder entrainment modify the composition of inclusions during the pouring, solidification and rolling processes. Precipitation of CaS is initiated during the solidification process of molten steel. The precipitation of MnS can only be found during the hot rolling process. Inclusions in the interior of the rolled billet are more and larger than those in the subsurface of rolled billet. The inclusion index increases from the rear to the head of the rolled billet (from the bottom to the top of the ingot). Furthermore, the inclusion index increases as the superheat increases. On the basis of the results, it is recommended that molten steel should be poured at a low superheat under the protection of argon shroud. Furthermore, attention may be paid to the way of adding the mold powder.
Les instabilités hydrodynamiques dans les écoulements granulaires géophysiques
Authors: Viroulet Sylvain , Baker James L. , Edwards Andrew N. , Gray J.M.N.T.
Published: July 2019

De par le vaste champ d’applications qu’elle offre, l’étude des écoulements granulaires a connu une expansion considérable au cours de ces vingt dernières années, autant du point de vue industriel que géophysique. Ces écoulements granulaires ont une grande influence dans le monde qui nous entoure. Or, différentes instabilités hydrodynamiques peuvent naitre en leur sein, entrainant alors des changements importants des propriétés mêmes de l’écoulement. Les instabilités dues à la ségrégation par taille de particules, le développement d’ondes de surface ou encore l’apparition de ressauts dans l’écoulement en sont des exemples marquants.
Möglichkeiten und Management gefäßrekonstruktiver Eingriffe im Rahmen viszeralchirurgischer Operationen und ihrer perioperativen Betreuung – eine selektive Auswahl repräsentativer Fallkonstellationen
Authors: Barth Udo , May Jens Peter , Albrecht Roland , Pech Maciej , Halloul Zuhir , Meyer Frank
Published: July 2019

Einleitung Das Ineinandergreifen der chirurgischen Fachdisziplinen bei der Bewältigung komplexer, chirurgisch therapierbarer Erkrankungen ist eine eminente Voraussetzung, um die Erfolgschancen der Behandlung zu steigern. Bei der zunehmenden Erweiterung der Indikationsgrenzen zur operativen Behandlung von ausgedehnten multiviszeralen Tumoren, bei iatrogenen Gefäßverletzungen im viszeral- und onkologisch-chirurgischen Operationsfeld und der mesenterialen Ischämie ist eine gefäßchirurgische Expertise vonnöten.

Zielsetzung Narrative Übersicht auf Basis aktueller wissenschaftlicher Referenzen und eigener klinischer und operativer Erfahrungen im entscheidungstechnischen Herangehen zum taktischen Vorgehen und zu gefäßrekonstruktiven Möglichkeiten bei viszeralchirurgischen Eingriffen.

Ergebnisse Beim Pankreaskarzinom mit seiner anhaltend schlechten Prognose ist die R0-Resektion die einzig kurative Therapieoption – damit werden intraoperativ erweiterte Anforderungen an den Chirurgen gestellt. Während die arterielle Gefäßrekonstruktion aufgrund erhöhter Morbidität und limitierter Evidenz weiter in der Diskussion und spezifischen Fallkonstellationen vorbehalten bleibt, ist die venöse Rekonstruktion mittlerweile etabliert. Auch bei ausgedehnten retroperitonealen Sarkomen ist im Rahmen multiviszeraler Resektionen die Rekonstruktion der infiltrierten V. cava inferior oder A. iliaca communis durch eine Patchplastik oder autologen Bypass-/Segmentersatz notwendig. Im Rahmen von inflammatorischen Prozessen sowie Tumoradhäsionen/-infiltrationen zu angrenzenden anatomischen Strukturen können intraoperative Gefäßverletzungen oder postoperative Gefäßalterationen auftreten, deren Rekonstruktion durch anatomische Varianten erschwert wird. Die extrem hohe Anforderung an den Viszeralchirurgen bei mesenterialen Ischämien wird durch eine kompetente Beurteilung der mesenterialen Gefäßstrecke auf Basis einer adäquaten Bildgebung und durch den Zeitfaktor bestimmt. Ein promptes rekanalisierendes Vorgehen entscheidet mit über die Prognose des Krankheitsbildes.

Schlussfolgerung Gefäßrekonstruktionen in der Viszeralchirurgie, insbesondere der Tumorchirurgie, stellen hohe Anforderungen an die Expertise des Operateurs. Eminent dabei ist neben einer guten präoperativen Diagnostik eine entwickelte spezifisch gefäßchirurgisch-medizinische wie auch fachübergreifende Erfahrung in Fallmanagement und in der OP-Taktik/-Technik.
Laparoskopisches Ausschalten eines Aneurysmas der A. lienalis
Authors: Ellebrecht David Benjamin , Horn Marco , Pross Moritz , Keck Tobias , Kleemann Markus
Published: July 2019

Zielsetzung Viszeralarterienaneurysmata stellen seltene, jedoch gefürchtete Gefäßpathologien dar. Am häufigsten sind die Äste des Truncus coeliacus und in diesem Zusammenhang die A. lienalis betroffen. Meist werden Viszeralaneurysmata erst diagnostiziert, wenn eine Blutungskomplikation durch die Aneurysmaruptur auftritt. Folglich wird bei einer vorherigen Detektion eine frühzeitige Ausschaltung nach Diagnosestellung empfohlen. Als primäres Verfahren bietet sich hierbei die endovaskuläre Ausschaltung an. Falls eine endovaskuläre Ausschaltung nicht möglich ist, kann auch durch eine chirurgische Ausschaltung das Viszeralaneurysma erfolgreich therapiert werden.

Indikation Nachgewiesenes Milzarterienaneurysma im Hilusbereich. Ein endovaskuläres Coiling hätte voraussichtlich eine Ischämie der Milz bedingt.

Methode Laparoskopische Ausschaltung des Milzarterienaneurysmas.

Schlussfolgerung Bei für endovaskuläre Therapie nicht geeigneten Pathologien der A. lienalis stellt die laparoskopische Ausschaltung eine sicher und effektiv durchführbare minimalinvasive Option dar.
Klinische Wirksamkeit von „FlexiTeam“ (Home Treatment und intensivierte ambulante Behandlung) – Vergleich einer Behandlung in einem Modellprojekt nach § 64b in Berlin mit der stationären Behandlung
Authors: Weinmann Stefan , Wiedmann Simon , Breidert Tilo , Bohe Matthias , Pfeiffer Jan , Rosenberger Eva , Bechdolf Andreas
Published: July 2019

Ziel der Studie Verglichen wurde die klinische Wirksamkeit von „Home Treatment“ (HT) zusammen mit intensiver ambulanter Behandlung (IAB) im Modellprojekt „FlexiTeam“ (FT) mit einer stationär-psychiatrischen Routinebehandlung.

Methodik Im Rahmen einer kontrollierten gematchten Vorher-Nachher-Studie wurden Routinedaten von jeweils 83 Patienten im FT und in der stationär-psychiatrischen Routinebehandlung hinsichtlich (teil-)stationärer Wiederaufnahmerate und Verweildauer im 6- und 12-Monats-Follow-up verglichen.

Ergebnisse Es zeigt sich keine signifikante Reduktion der (teil-)stationären Verweildauer im Index-Aufenthalt. Durch die Behandlung im FT konnte eine signifikante Reduktion sowohl der (teil-)stationären Wiederaufnahmerate als auch der Verweildauer im 6- und 12-Monats-Follow-up erreicht werden.

Schlussfolgerung Eine flexible Kombination aus IAB und HT stellt eine wirksame Ergänzung zur stationär-psychiatrischen Routinebehandlung dar und kann bei geeigneten Patienten das Risiko stationärer Wiederaufnahmen senken.
Unicompartmental Knee Replacement Combined to Anterior Cruciate Ligament Reconstruction: Midterm Results
Authors: Ventura Alberto , Legnani Claudio , Terzaghi Clara , Macchi Vittorio , Borgo Enrico
Published: July 2019

A study was conducted to retrospectively evaluate the outcomes of combined medial unicompartmental knee replacement (UKR) and anterior cruciate ligament (ACL) reconstruction. The hypothesis was that this procedure would lead to satisfying results in patients affected by medial osteoarthritis and ACL insufficiency. Fourteen patients with ACL deficiency and concomitant medial compartment symptomatic osteoarthritis were treated from 2006 to 2010. Twelve of them were followed-up for an average time of 7.8 year (range: 6–10 years). Assessment included Knee Osteoarthritis Outcome score (KOOS), Oxford Knee score (OKS), American Knee Society scores (AKSS), Western Ontario and McMaster (WOMAC) index of osteoarthritis, Tegner's activity level, objective examination including instrumented laxity test with KT-1000 arthrometer, and standard X-rays. KOOS score, OKS, WOMAC index, and the AKSS improved significantly at follow-up (p < 0.001). There was no clinical evidence of instability in any of the knees as evaluated with clinical and instrumented laxity testing (p < 0.001). No pathologic radiolucent lines were observed around the components. In one patient, a total knee prosthesis was implanted due to the progression of signs of osteoarthritis in the lateral compartment 3 years after primary surgery. UKR combined with ACL reconstruction is an effective therapeutic option for the treatment of combined medial unicompartmental knee osteoarthritis and ACL deficiency and confirms subjective and objective clinical improvement up to 8 years after surgery. This study reflects level IV evidence.
Study on mixed lubrication characteristics of piston/cylinder interface of variable length
Authors: Sun Shiqing , Sun Na , Wang Xiaoli
Published: July 2019

Aiming at the lubrication problem of piston/cylinder interface of variable length, a two-dimensional mixed lubrication model was established. This model considers the adaptive eccentricity and the force balance of the piston. The calculation procedure for solving the average Reynolds equation and the nonlinear dynamic equations is established by the finite difference method and the global Newton-Raphaon method. The effects of load pressure and tilting angle of the swash plate on lubrication performance were investigated. The results show that when the supply pressure increases to the maximum, the minimum oil film thickness has a relatively small value. The results further indicate that increasing the lubrication area can decrease the inclination of the piston and the peak pressure of the oil film. Increasing the load pressure and the tilting angle of the swash plate can reduce the minimum oil film thickness and increase the friction force.
Bose-Einstein condensation of mexons in hematite at +210 °C
Authors: Andrienko A. V. , Safonov V. L.
Published: July 2019

The parametric excitation of magnetoelastic waves in antiferromagnetic hematite was studied using oblique microwave pumping at high temperatures. It was found that at a certain overthreshold pump power, the lowest magnetoelastic eigenmode of the sample, whose frequency is three orders of magnitude lower than the pump frequency, is intensively excited. We interpret this phenomenon as Bose-Einstein condensation of mexons, quanta of magnetoelastic waves.
Theoretical analysis of tensor perturbations for uncertainty quantification of Reynolds averaged and subgrid scale closures
Authors: Mishra A. A. , Iaccarino G.
Published: July 2019

With the advent of improved computational resources, alternate design approaches that explicitly account for uncertainty in predictions, such as robust- and reliability-based design, are superseding deterministic design approaches in aerospace applications. In this context, accounting for the structural uncertainties in turbulence models has been identified as the greatest challenge toward simulation based design. At present, the primary methodology to estimate the structural uncertainty in turbulence models is based on tensor perturbations applied to the modeled Reynolds stress tensor. This methodology has been applied with success to a variety of problems in engineering analysis and design under uncertainty. However, the modeling rationale of this perturbation approach is still not unearthed. While we know that the procedure works in generating uncertainty estimates that account for the discrepancy in turbulence simulations, we do not know why it works or even how exactly it works. This may lead to its application to cases of turbulent flows or under conditions where it should not perform well. This could potentially lead to analyses that are misleading, or even designs that are hazardous. In this article, we outline the underlying modeling structure represented by this tensor perturbation procedure. The exact limitations addressed by each step of the perturbation methodology are isolated and explicated. This analysis enables us to identify the limitations of this procedure and outline the specific phenomena and types of turbulence model uncertainty where its application would be equivocal. Additionally, we outline how this enables us to derive quasirealizability conditions on the perturbations.
Large area deep ultraviolet light of Al0.47Ga0.53N/Al0.56Ga0.44N multi quantum well with carbon nanotube electron beam pumping
Authors: Yoo Sung Tae , So Byeongchan , Lee Hye In , Nam Okhyun , Chang Park Kyu
Published: July 2019

Large area deep ultraviolet (DUV) light is generated by carbon nanotube (CNT) cold cathode electron beam (C-beam) irradiation on Al0.47Ga0.53N/Al0.56Ga0.44N multi quantum wells (MQWs) anode. We developed areal electron beam (EB) with CNT cold cathode emitters. The CNT emitters on silicon wafer were deposited with an area of 188 mm2, and these were vertically aligned and had conical structures. We optimized the C-beam irradiation conditions to effectively excite AlGaN MQWs. When AlGaN MQWs were excited using an anode voltage of 3 kV and an anode current of 0.8 mA, DUV with a wavelength of 278.7 nm was generated in a large area of 303 mm2. This DUV area is more than 11 times larger than the light emitting area of conventional EB pumped light sources and UV-LEDs.
Deeper understanding of turbulence modeling works to improve simulation based design
Authors: Mandel Savannah
Published: July 2019

An analysis of tensor perturbation methodology is used to improve error estimates for turbulence models and enhance the safety of engineering designs.
Ibrāhīm Sulṭān’s Muṣḥaf: TheQurʾānCalligraphed by Ibrāhīm Sulṭān in the Pars Museum
Authors: Mirza-Abolqasemi Mohammad Sadeq
Published: July 2019

This article presents a very rare manuscript of aMuntakhab al-Suwar(selection of Qur’anic chapters) calligraphed by Ibrāhīm Sulṭān b. Shāhrukh. This manuscript was transcribed in large format in Ramaḍān 830 AH/June 1427 AD and endowed to the holy shrine of Shāh-Chirāgh in Ramaḍān 834 AH/May‒June 1431 AD. Therefore, it is considered to be one of the last known works calligraphed by Ibrāhīm Sulṭān. It is kept in the Pars museum in Shiraz. In this article, the unique codicology and special characteristics of this masterpiece are studied, and the important historical aspects of Ibrāhīm Sulṭān and the art works attributed to him are elaborated. The style of his calligraphy will also be examined to find out the sources of inspiration for his distinct style.
A new field test to estimate the aerobic and anaerobic thresholds and maximum parameters
Authors: Giovanelli Nicola , Scaini Stefano , Billat Veronique , Lazzer Stefano
Published: July 2019

Evaluation of cardiorespiratory parameters is important in athletic population in order to monitor the training status and define training intensities. The aim of this study was to validate an easy‐to‐perform running test called RABIT® (Running Advisor Billat Training) for detecting aerobic (AerT) and anaerobic (AnT) threshold and maximum parameters. Fifteen trained runners completed a graded (GRAD) and RABIT test (four self‐selected pace steps: (i) 10 minutes at free warm‐up pace, (ii) 5 minutes at medium pace, (iii) 3 minutes at hard pace, (iv) 10 minutes at easy pace). We compared the cardiorespiratory parameters and running speed of the RABIT with those corresponding to AerT, AnT or maximum parameters obtained by the GRAD. The ⩒O2max, HRmax, RERmax and running speed max measured during the 3‐minute hard pace of the RABIT were not statistically different from the maximum parameters measured during GRAD (p > 0.05). The ⩒O2, HR and RER measured during the medium and easy pace of the RABIT were not significantly different from the AnT and AerT parameters measured during GRAD. In conclusion, RABIT was validated for all the maximum parameters and for most of Ant‐ and AerT‐related parameters and then it might be used for detecting training zones in athletes.
Acetylcholinesterase is not a generic marker of extracellular vesicles
Authors: Liao Zhaohao , Jaular Lorena Martin , Soueidi Estelle , Jouve Mabel , Muth Dillon C. , Schøyen Tine H. , Seale Tessa , Haughey Norman J. , Ostrowski Matias , Théry Clotilde , Witwer Kenneth W.
Published: July 2019

Acetylcholinesterase (AChE) activity is found in abundance in reticulocytes and neurons and was developed as a marker of reticulocyte EVs in the 1970s. Easily, quickly, and cheaply assayed, AChE activity has more recently been proposed as a generic marker for small extracellular vesicles (sEV) or exosomes, and as a negative marker of HIV‐1 virions. To evaluate these proposed uses of AChE activity, we examined data from different EV and virus isolation methods using T‐lymphocytic (H9, PM1 and Jurkat) and promonocytic (U937) cell lines grown in culture conditions that differed by serum content. When EVs were isolated by differential ultracentrifugation, no correlation between AChE activity and particle count was observed. AChE activity was detected in non‐conditioned medium when serum was added, and most of this activity resided in soluble fractions and could not be pelleted by centrifugation. The serum‐derived pelletable AChE protein was not completely eliminated from culture medium by overnight ultracentrifugation; however, a serum “extra‐depletion” protocol, in which a portion of the supernatant was left undisturbed during harvesting, achieved near‐complete depletion. In conditioned medium also, only small percentages of AChE activity could be pelleted together with particles. Furthermore, no consistent enrichment of AChE activity in sEV fractions was observed. Little if any AChE activity is produced by the cells we examined, and this activity was mainly present in non‐vesicular structures, as shown by electron microscopy. Size‐exclusion chromatography and iodixanol gradient separation showed that AChE activity overlaps only minimally with EV‐enriched fractions. AChE activity likely betrays exposure to blood products and not EV abundance, echoing the MISEV 2014 and 2018 guidelines and other publications. Additional experiments may be merited to validate these results for other cell types and biological fluids other than blood.
The effect of boron dopant on hydrogenated graphene for hydrogen storage application
Authors: Susilo D N A , Ganta M , Sunnardianto G K , Handayani M
Published: July 2019

We investigate the effect of boron dopant on the charge transfer and reaction pathways of hydrogenated graphene based upon density functional theory calculation. We focused on the particularly the charge transfer rate of trimer hydrogen adsorption and its reaction pathways. Firstly, we investigated the effect of B dopant on the pristine graphene which is revealed that B-C bond length prior to hydrogenation is around 1.49 Å resulting the deformed structure of graphene since the size of boron is a bit larger that carbon atom. We have also calculated the charge transfer (CTR) from hydrogen to carbon atom after boron subtitution, we found that there is an increasing the CTR with respect to the pristine graphene indicated that the strong bond length between hydrogen and carbon.
Effect of solution treatment on microstructure and corrosion behaviour of Mg-9Al-1Zn alloys
Authors: Naldi R , Anawati A
Published: July 2019

The effect of solution treatment on the microstructure and corrosion behavior of cast Mg-9Al-1Zn (AZ91) were studied by using electro-optical microscopy, X-ray diffraction (XRD) technique, and weight loss method. The solution treatment was done at 415°C for 2 h followed by a water quench. The as-cast AZ91 alloy composed of α-Mg phase and β-phase (Mg17Al12). Most of the β-phase was segregated along the grain boundaries. A significant reduction in the volume fraction of β-phase was obtained as a result of solution treatment. The β-phase precipitate was distributed randomly both at grain boundaries and in the grain interior as discrete particles of a few µm sizes. The solution treatment induced grain growth resulting in a significantly larger equiaxed grain in the range 100-500 µm. A higher corrosion rate was obtained for the solution treated alloy than the untreated one. The β-phase precipitate played a dual role in the corrosion of AZ91 alloy depending on its volume fraction in the alloy. A nearly continuous distribution of β-phase along grain boundaries in the as-cast alloy served as a barrier for corrosion across grain while the distribution of discrete particles in the solution-treated alloy accelerated corrosion in the surrounding matrix.
Relaxation behavior of natural rubber composites based on mooney stress relaxation and rheometer data
Authors: Indrajati I N , Setyorini I
Published: July 2019

Studies on relaxation behavior of natural rubber composites were conducted by Mooney stress relaxation coupled with rheometer data. The effect of filler (carbon black N-330) and sulphur loading was monitored on the relaxation behavior. Elasticity of the composites was also determined in term of elongation at break and hardness, as confirmation to the relaxation behavior. The experiments were conducted by varying the N-330 30, 35, 40 and 45 phr with the sulphur baseline of 2 phr. While sulphur loading was varying from 1, 2, 3 and 4 phr with the N-300 baseline of 30 phr. Mooney experiments were carried out at 100 ºC, while rheometer experiments were conducted in a moving die rheometer at 150ºC. Results finding showed that the relaxation rate was reduced with N-330 loading or sulphur loading due to restriction of rubber molecule chain mobility by crosslinking formation. N-330 provided higher effect on stress relaxation rate compared to sulphur. Elongation of the composites was found to decrease upon filler or sulphur loading, while hardness was inversely.
Effect of Punch Parameters on Springback for Mild Carbon Steel in A V-Shape Bending Process
Authors: Suyuti M A , Iswar M , Nur R
Published: July 2019

The springback is variably sensitive to materials and process parameters. Considering springback occurred in a formed part is significant for designing tools and dies. In this paper, experiments of a V-shape bending test were performed for investigating the springback effect. The punch parameters variation has been observed in ASTM A-36 mild carbon steel. Punch radius used and punch angle). The V-shape bending of mild steel was performed using Universal Testing Machine (UTM) at various punch radius (2, 4, and 6 mm) and punch angle (80°, 85°, and 90°) and at constant of die radius (10 mm) and die width (50 mm). The experimental result indicates that the punch radius has a most significant impact on springback behaviour of these sheet metal. This is verified through our experimental work using V-shape bend testing.
Erosion behaviour of alumina ceramic coating on mild steel by the modified composition of phosphate binder
Authors: Idamayanti D , Ginanjar D , Bandanadjaja B , Purwadi W , Lilansa N
Published: July 2019

The Pulverizer pipe made of mild steel had erosion failure due to coal dust impacting, thus its service life also reduces. The ceramic coating overlay on the surface of mild steel is one of the appropiate ways to protect the mild steel from erosion. This research is aimed to perform a ceramic coating over the surface of the mild steel using a dipping method to improve its erosion resistance by using the alumina-phosphate ceramic coating. The coating layer is formed by the reaction between monoaluminum phosphate (MAP) as a binder and Al2O3 particles. It transforms into berlinite phase when heated at an elevated temperature. The observation is carried out with the variation of the MAP binder composition Al:P 25:75, 28:72, 30:70 and the Al2O3/MAP slurry is given at 40/60. Scanning electron microscopy is used to characterize the coating morphology. X-ray diffraction is applied to investigate the ceramic coating phases. The gas erosion jet measures erosion resistance of the ceramic coating. From the test result, it can be concluded that the binder composition influenced the erosion behaviour of alumina ceramic coating, the binder with Al:P (30:70) showed the erosion resistance increasing four times compared to the condition without coating.
Optimization of ZnO-nanorods addition toward Li4Ti5O12 (LTO) performance using sol-gel solid state method as half-cell lithium-ion battery anode
Authors: Priyono B , Panjaitan A A S , Syahrial A Z , Faizah  , Subhan A
Published: July 2019

Performance optimization for the anode of lithium-ion batteries (LIBs) can be conducted by adding ZnO through sol-gel solid-state reaction. In this research, the Li4Ti5O12 (LTO) used was synthesized through the sol-gel solid-state process and added with ZnOnanorods obtained ZnO synthesis after LTO synthesis done. LTO-ZnO obtained was characterized to determine the main phase and chemical composition by XRD and SEM-EDS respectively. Electrochemical performance of LTO-ZnO was tested by EIS, CV, and CD. ZnOnanorods characterization with SEM-EDS results shows that the ZnO inside the LTO dispersed homogeneously. Characterization using XRD revealed that the ZnO successfully enter the LTO with the variation of the amount of 4, 7, and 10 wt% of ZnO. Electric conductivity test shows improvement at an optimum addition amount of ZnO at 4 wt%, although BET result shows at the optimum amount of surface area with 75.545 m2/g. Electrochemical performance result shows optimum performance in ZnO at 4 wt% for its ability to withstand EIS test at 20C compared to 7 wt% and 10 wt%. Also, the capacity of 4 wt% added is 110.2 mAh/g compared to 7 wt% with 109.1 mAh/g and 10 wt% with 96.7 mAh/g.
Fabrication, microstructure and corrosion study of porous Mg-Ca-Zn using CaCO3 pre-treatment with sodium trisilicate
Authors: Erryani A , Al-aziz I , Lestari F P , Kartika I
Published: July 2019

Magnesium-based alloys have the good potential as a biodegradable implant that can be degraded in biological tissue. In this research, the fabrication of porous implant materials based on Mg-Ca-Zn alloy develop by powder metallurgy. CaCO3 as a foaming agent which previously coated by using sodium trisilicate has been used to obtain open celullar pores. The alloy compositions used in this research are Mg-Ca-3Zn-5CaCO3 and Mg-Ca-3Zn-10CaCO3. Sintering process is carried out at temperature of 600, 650 and 700 °C with holding time of 5h. The alloy is characterized by using XRD (microstructure analysis), SEM (surface and pore analysis) and corrosion test of alloys (electrochemical analysis using tafel graph). The microstructures of the alloy show MgO and Mg2Ca phase SEM results show the pores in the alloy with the size approximately arround 194.843-266,938μm. The corrosion rate in alloys is obtained in the range of 0.4-3.2 mmpy. The morphology of the alloy surface after corrosion process shows the volcano type. The corrosion process occurs localized where the electrochemical reaction occurs, so as to form a distinctive structure with the shape of the circle and the hole in the middle.
Ductility improvement of high density polyethylene (HDPE)-modified bitumen through adding modified lignin
Authors: Septimorien E A , Friskila L M D , Natasya B , Chalid M
Published: July 2019

High Density Polyethylene (HDPE) is added to bitumen to improve the mechanical properties as Polymer Modified Bitumen (PMB), but both of them have different chemical properties. To achieve best mechanical properties of the mixture coupling agent is needed such as lignin that has bipolar characteristic. In the previous research, unmodified lignin tendency of polarity is bigger thus modified with polyurethanee PEG to increase its non-polar parts. In order to confirm the potential of modified lignin as a coupling agent for HDPE-Modified Bitumen. Several stages of this experiment consists of sample preparation, characterization of raw materials, mixing, and characterization of the PE-Modified Bitumen. This experiment used hot melt mixing to mix modified lignin, HDPE, and bitumen. The result of this experimental was analysed by using Ductility test, FTIR and FESEM. The addition of modified lignin to HDPE-Modified Bitumen increase distribution and dispersion of HDPE particulates inside bitumen matrix, increasing PMB HDPE mechanical properties. Furthermore, FESEM characterization indicated that the addition of modified lignin gave better mixing of PE-Bitumen. FTIR showed an increase of intensities at non-polar peaks, and down at polar peaks compared with unmodified lignin. Ductility test showed that modified lignin has better compatibility as coupling agent than unmodified lignin. From this experiment, modified lignin can improve mixing between HDPE and Bitumen better than modified lignin. So, we can use modified lignin as the new coupling agent.
The Influence of Sn addition on the microstructure and mechanical properties of the new β-type Ti-Mo-Nb based alloys for implant material
Authors: Sutowo C , Senopati G , Supriadi S , Pramono A W , Suharno B
Published: July 2019

Titanium alloys are very interesting for biomedical applications due to excellent biocompatibility, corrosion resistance, lower density, and lower young modulus compared to cobalt and stainless steel alloys. However, compared to bone, young modulus of pure titanium and Ti-6Al-4V are still relatively high and the mechanical properties are still insufficient to meet the needs of biomaterials replacing the hard tissues. In this paper, a newly Ti-Mo-Nb based alloys were designed and the effect of Sn content in Ti-6Mo-6Nb-xSn alloys (x = 0,4,8 and 12 wt%) after homogenized on microstructure, hardness, and young modulus were investigated. The alloys were produced by electric vacuum arc furnace with non-consumable tungsten electrode then homogenized at 1100 °C for 7 under controlled argon atmosphere. Optical microscope, scanning electron microscopy, x-ray diffraction hardness test and ultrasonic test were used for alloys characterization. The results showed that Ti-6Mo-6Nb-xSn has equiaxed structure and Sn addition could promote the formation of β phase. The elasticity modulus of Ti-6Mo-6Nb-xSn alloy with the addition of 12% Sn was 88 GPa, this is better since it is below the elastic modulus of Ti6Al4V implant material.
Thermal characteristics of ferronickel slag on roasting process with addition of sodium carbonate (Na2CO3)
Authors: Prasetyo A B , Maksum A , Soedarsono J W , Firdiyono F
Published: July 2019

Thermal characterization of ferronickel slag waste has been studied using TG / DTA, XRD, and SEM-EDX. The characterization of the initial samples of ferronickel slag was carried out TG / DTA to 1200°C. The result obtained is at a temperature of 800°C, there is an increasing mass and up to 4.68% at a temperature of 1200°C. At temperature of 807.4°C to 845.8°C, an exothermic reaction occurs. The increasing mass is due to the ferronickel slag which is originally in the form of metal, and then it was roasted to undergo an oxidation reaction so that the metal that has been formed, it returned into oxides. So that the weight of the sample mass increase. Samples of ferronickel slag added with sodium carbonate were also analyzed using TG / DTA. The results obtained are 2 endothermic peaks at temperatures of 90.6°C and 858.9°C with a total mass reduction of 49.3%. At a temperature of 90.6°C, there is a heavy loss caused by 2.38% loss of surface water. The XRD result of ferronickel slag is composed of enstatite (MgSiO3), forsterite (Mg2SiO4), fayalite (Fe2SiO4), and quartz (SiO2) structures. From the XRD analysis, the composition of silica oxide associates with magnesium and iron in the form of enstatite, forsterite, and fayalites is a very dominant composition. The roasting process of a mixture of ferronickel slag with sodium carbonate was carried out by heating at a temperature of 800-1000°C for 1 hour, and the sample result of roasting were analyzed using XRD. The result of roasting shows that the roasting process takes place more perfectly at higher temperature; it is indicated by the increasing phase intensity of SiO2 and the formation of sodium silicate (Na2SiO3). The result of SEM shows that the higher the temperature, the distribution of Na, Si, and O elements tend to cluster in the same place or spot, while the elements of Mg, Si, and O are less bonded.
Investigations on mineralogical characteristics of Indonesian nickel laterite ores during the roasting process
Authors: Setiawan I , Febrina E , Subagja R , Harjanto S , Firdiyono F
Published: July 2019

Nickel is obtained from laterite ores by a metallurgical process to produces ferronickel. Nickel metal is present in a carrier mineral, a nickel magnesium silicate hydrate compound called garnierite. Garnierite is the common name of magnesium silicate hydrate minerals including chlorite, clay and serpentine. This study to investigate the phase formed when the nickel ore is roasted from a temperature of 600°C to a temperature of 1000°C under atmospheric enviromental. Microscopic analysis of roasted samples was analyzed by SEM-EDX and the dehydroxylation and recrystallization was studied using DTA-TGA. The endothermic peak was appear at 78.8°C, 293.7°C and 638.0°C, this corresponds to the release of free water and the release of crystalline water. While the exothermic peak occurs at 828.0°C. The exothermic temperatures associated with structural changes due to dihydroxylation of serpentine into a forsterite phase. Based on the XRD graph it is known that the sample of the roasting will produce the olivine and forsterite phases.
The effect of iron content on the reduction of nickel laterite by direct reduction method
Authors: Setiawan I , Febrina E , Prasetyo A B , Subagja R , Firdiyono F
Published: July 2019

Reduction and the compounds formed when the reduced laterite nickel has been investigated. Nickel laterite with average grain size below 0.149 mm mixed with 13% (weight percent) of coal as reductant then reduced in muffle furnace with temperature from 700 °C to 1000 °C. Type of laterite is used which has high iron (saprolite) and low iron content (limonite). Reaction time varied 30, 60 and 90 minutes. The reduction of nickel during reduction is determined by an analysis of metallization values. Metallization analysis used bromine methanol method, while the compound analysis was formed using x-ray Diffractometer. Based on the metallization test, it is known that the laterite nickel ore containing high iron will produce a higher nickel reduction than the laterite nickel ore containing low iron. This corresponds to the oxide phases formed. The higher iron contain on the ore tend to produce the fayalite mixture and slightly forsterite, while at low iron content will form a forsterite. Forsterite tends to inhibit reduction of nickel.
Characteristic of Ti-6Al-6Nb alloys following solution treatment with cryogenic cooling for implant applications
Authors: Rokhmanto F , Arief H , Alfirano  , Sutowo C
Published: July 2019

Titanium alloys are widely used as implant materials, due to the mechanical properties, one of which is the low elastic modulus. The differences in the elastic modulus of Titanium alloys and Bones are wide enough, therefore it’s necessary to investigate how to obtain a lower Titanium elastic modulus. In this paper used Ti-6Al-6Nb alloys as an implant material. The Ti-6Al-6Nb alloys Solution Treated at 1100°C, following cryogenic cooling with liquid Nitrogen. Before that The Ti-6Al-6Nb alloys Homogenized at 1100°C for 12 hours, then Hot rolled with preheated at 1100°C for 30 minutes. As comparison Solution Treatment also done in the ice water cooling and air cooling. The Ti-6Al-6Nb alloys characterized with a hardness test, metallographic and ultrasonic test to obtain the elastic modulus. The analysis shows that the lowest elastic modulus was 100,19 GPa and highest hardness was 52,54 HRc is in the cryogenic cooling process due to the beta phase formed.
Decomposition of spodumene mineral in granitic rocks from South Kalimantan - Indonesia by potassium sulphate
Authors: Suharyanto A , Lalasari L H , Mubarok M Z
Published: July 2019

The decomposition behaviour of spodumene mineral in granitic rock from Kalimantan Indonesia by using potassium sulphate has been studied in this research. The granitic rock from Kalimantan is indicated to contain spodumene mineral. The sspodumene is one of the main minerals which contains lithium. The purpose of this study is to decompose the α-spodumene mineral in the granitic rock of Kalimantan to β-spodumene which is subsequently easier to be dissolved in water. In this study, the decomposition of α-spodumene was performed under variations of roasting temperatures (i.e. 350°C, 450°C, 550°C, 600°C, 700°C, 800°C, 900°C and 1000°C) and roasting times (20 min, 40 min and 60 min). The results of the decomposition products were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), inductively coupled plasma optical emission spectroscopy (ICP-OES), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). It was identified that the granitic rock from Kalimantan consists of α-spodumene (LiAlSi2O6) with lithium content of 3.09 ppm and the other major minerals are quartz (SiO2) and albite (NaAlSiO3O8). The α-spodumene was completely converted to β-spodumene at 700°C for 60 minutes.
Efficiency and characterization study of low voltage current sacrificial anode on Al-Zn-Cu and Al-Zn-Si alloy
Authors: Ferdian D , D Yudha R , M Ario W , Yunita T , Sulistijono
Published: July 2019

The sacrifice of the anode is the cathodic protection used to prevent corrosion. Al-Zn-In alloys are often used it causes excessive protection that can increase the possibility of hydrogen embrittlement in high-strength steel. Therefore, the solution is to use aluminum alloys with low voltage current. The purpose of this research is to know the efficiency of aluminum sacrificial anode with alloy elements Zn, Si and Cu as low voltage current. As well as studying the potential of Al alloys with elements Zn, Cu and Si can be used as sacrificial anodes at sea water conditions. Testing methods performed are Optical Emission Spectroscopy testing, weight loss testing, efficiency testing, Electrochemical Impedance Spectroscopy testing, and metallographic testing. From this research, we found the result of Al-Zn-Cu alloy which has electrochemical capacity and best efficiency is Al-5Zn-0,1Cu Alloy for 2795 Ah / kg with 98% efficiency and Al-Zn-Si alloy with capacity value electrochemistry and the best efficiency is Al-5Zn-0.1Si alloy for 2808 Ah / kg with 98% efficiency. The lowest value of transfer resistance is found in Al-5Zn-0.1Cu alloy and Al-5Zn-0.1Si alloy with the value of 1012.7 Ω and 1092.9 Ω and the double capacitance value in the smallest Al-Zn-Cu alloy is alloy Al-5Zn-0.5Cu with the value of 13.2 μMho while in Al-Zn-Si alloys are present in Al-5Zn-0.5Si with the value of 19 μMho. With the structure obtained is the greater the addition of Cu and Si, the more rough and corroded surface sacrificial anodes.
The application of zinc oxide layer as ethylene sensor
Authors: Sholehah A , Pusparasmi D A , Yuliarto B
Published: July 2019

As an emerging n-type semiconductor, ZnO has been widely applied in sensor area. In this study, we prepared an ethylene sensor using ZnO layer on FTO glass substrate. The seed layer was deposited using simple electrodeposition method using voltage of -1.1 V for 2 hours in cold bath (6°C). The ZnO layer was further grown using CBD technique at 90°C for 2 hours. In order to observe the effect of structural manipulation on the sensor performance, some of the ZnO layer samples were undergoing hydrothermal treatment at 100ºC for 1 hour under 1 bar N2 gas. After annealing process, all ZnO layers were exposed with 50 ppm ethylene gas in closed chamber. Based on the results, it is shown that the optimum ZnO layer has been successfully identified the ethylene gas in concentration of 50 ppm, with response value of 2.40% at 200°C.
Corrosion resistance of epoxy primer, polyurethane, and silyl acrylate anti-fouling on carbon steel
Authors: Devanny S , Riastuti R
Published: July 2019

Anti-fouling paint is commonly applied as a protective coating on steel structures in the marine environment; one of the anti-fouling paint materials is silyl acrylate copolymer which can hydrolyse with seawater and form leaching layers to release biocide pigments. This study evaluates a three-layer paint comprised of epoxy primer, polyurethane, and silyl acrylate anti-fouling on carbon steel plates through polarization measurements and a salt spray test. Linear polarization measurements are carried out on an unscribed specimen with a potential range of -1.0 to 1.0 Volts. The salt spray test is conducted on scribed specimens, lasts 168 hours, and involves periodic visual observation. The polarization analysis shows pseudo-passive behavior in a system that represents, first, the less protective passive layer of primer and, second, the progressive erosion of a leaching layer of the anti-fouling paint which exposes a new layer beneath. The salt spray test shows that the three-layer paint has poor corrosion resistance in the atmospheric environment indicated by peeled layers and the occurrence of underfilm corrosion since the 48-hour test period.