bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Behavior of Anhydrous Ascorbic Acid 6‐Palmitate with Trace of Decomposition
Authors: Ogawa Shigesaburo , Hirase Ryuji , Ohishi Tomoyuki , Hara Setsuko , Takahashi Isao
Published: August 2020

Ascorbic acid 6‐palmitate (AsP) is an industrially utilized antioxidant and amphiphilic lipid, which forms a liquid crystalline (LC) phase. Herein, we describe the basic thermal behavior of AsP under anhydrous condition. Grazing‐incidence wide‐angle X‐ray‐diffraction (GI‐WAXD) measurements using a two‐dimensional detector (2D‐GI‐WAXD) and perpendicularly aligned AsP films, together with thermal analysis, showed that the AsP forms only a lamellar LC phase above its melting point (Tm); however, when the LC phase was cooled to facilitate annealing and recrystallization, crystals (Cr) formed with a low degree of crystallinity. Furthermore, a composite system, consisting of the Cr phase and LC phase of AsP, was obtained upon reheating. These anomalous phenomena were likely caused by trace dimerization and decomposition of AsP at a temperature just above Tm, although thermal decomposition accompanied by weight reduction occurred at a much higher temperature in the isotropic phase (IL). Thus, the basic thermal behavior of AsP, which is essential for its use, was unveiled.
Growth of Highly Active Amorphous RuCu Nanosheets on Cu Nanotubes for the Hydrogen Evolution Reaction in Wide pH Values
Authors: Cao Dong , Wang Jiayi , Xu Haoxiang , Cheng Daojian
Published: August 2020

Rational design of low‐cost, highly efficient, and stable electrocatalysts for the hydrogen evolution reaction (HER) has attracted wide attention. Herein, 3D RuCu nanocrystals (NCs) are successfully synthesized by a facile wet chemistry method, in which amorphous RuCu nanosheets are directly grown on crystalline Cu nanotubes (NTs). Importantly, the obtained 3D RuCu NCs only need 18 and 73 mV to deliver the current density of 10 mA cm−2 for HER in alkaline and neutral media, respectively. Density functional theory calculations and experiments reveal that the Ru sites on the surface of amorphous nanosheets are the highly active centers for HER. Moreover, this catalyst can expose more surface area for water splitting compared to pure nanosheets because the unique 3D structure can effectively prevent the aggregation of nanosheets. Meanwhile, the interface between amorphous nanosheets and crystalline NTs is essential to boost the HER performance because the amorphous phase with many unsaturated bonds can facilitate adsorption of reactants and crystalline Cu with superior conductivity can promote the transfer of electrons. This work provides a facile method to prepare an original 3D Ru‐based electrocatalyst with highly active HER performance in wide pH values.
Skin‐Like Stretchable Fuel Cell Based on Gold‐Nanowire‐Impregnated Porous Polymer Scaffolds
Authors: Gong Shu , Du Shengrong , Kong Jianfei , Zhai Qingfeng , Lin Fenge , Liu Siyuan , Cameron Neil R. , Cheng Wenlong
Published: August 2020

Skin‐like energy devices can be conformally attached to the human body, which are highly desirable to power soft wearable electronics in the future. Here, a skin‐like stretchable fuel cell based on ultrathin gold nanowires (AuNWs) and polymerized high internal phase emulsions (polyHIPEs) scaffolds is demonstrated. The polyHIPEs can offer a high porosity of 80% yet with an overall thickness comparable to human skin. Upon impregnation with electronic inks containing ultrathin (2 nm in diameter) and ultrahigh aspect‐ratio (>10 000) gold nanowires, skin‐like strain‐insensitive stretchable electrodes are successfully fabricated. With such designed strain‐insensitive electrodes, a stretchable fuel cell is fabricated by using AuNWs@polyHIPEs, platinum (Pt)‐modified AuNWs@polyHIPEs, and ethanol as the anode, cathode, and fuel, respectively. The resulting epidermal fuel cell can be patterned and transferred onto skin as “tattoos” yet can offer a high power density of 280 µW cm−2 and a high durability (>90% performance retention under stretching, compression, and twisting). The results presented here demonstrate that this skin‐thin, porous, yet stretchable electrode is essentially multifunctional, simultaneously serving as a current collector, an electrocatalyst, and a fuel host, indicating potential applications to power future soft wearable 2.0 electronics for remote healthcare and soft robotics.
A Study on Potential Strip Shape Control of High‐Strength Steel during Hot Pinch Rolling Process
Authors: Kong Ning , Zhao Chuan , Cao Jianguo , Zhang Qingdong
Published: August 2020

Hot‐rolled high‐strength steel (HSS) strips always present side‐camber after they are cut into subsections along the rolling direction. To deal with the potential strip shape defect of hot‐rolled HSS, the nonlinear finite element (FE) software is applied to establish a 3D model of pinch roll and strips to simulate the pinch rolling process before the hot rolling coiler. The effects of temperature distribution, roll wear, friction coefficient, initial strip flatness defects, and tension on the strip longitudinal extension distribution are studied along the width direction. The results indicate that the pinch roll wear presents a great influence on both the tendency and quantitative value of the strip longitudinal extension distribution. The maximum unevenness value is 178%, and the maximum differences of longitudinal strain between the center and edge of the strips reach to 51.43%. A newly pinch roll contour is proposed to improve the potential strip shape defects. After the industrial application, the average pinch roll wear thickness decreases from 180 to 120 μm. The hot rolled strips are cut into substrips and the maximum side‐camber value decreases from 12 to 3 mm, which meets the requirement from the auto part manufacturers.
Prediction of pathological response to neo‐adjuvant chemoradiotherapy for oesophageal cancer using vibrational spectroscopy
Authors: Nguyen Thi N. Q. , Maguire Adrian , Mooney Catherine , Jackson Naomi , Lynam‐Lennon Niamh , Weldon Vicki , Muldoon Cian , Maguire Aoife A. , O'Toole D. , Ravi Narayanasamy , Reynolds John V. , O'Sullivan Jacintha , Meade Aidan D.
Published: August 2020

In oesophageal cancer (OC) neo‐adjuvant chemoradiotherapy (neoCRT) is used to debulk tumour size prior to surgery, with a complete pathological response (pCR) observed in approximately ∼30% of patients. Presently no predictive quantitative methodology exists which can predict response, in particular a pCR or major response (MR), in patients prior to therapy.

Raman and Fourier transform infrared imaging were performed on OC tissue specimens acquired from 50 patients prior to therapy, to develop a computational model linking spectral data to treatment outcome. Modelling sensitivities and specificities above 85% were achieved using this approach. Parallel in‐vitro studies using an isogenic model of radioresistant OC supplied further insight into OC cell spectral response to ionising radiation where a potential spectral biomarker of radioresistance was observed at 977 cm−1.

This work demonstrates that chemical imaging may provide an option for triage of patients prior to neoCRT treatment allowing more precise prescription of treatment.
Queer identity inclusion in the EFL classroom: Vietnamese teachers’ perspectives
Authors: Tran‐Thanh Vu
Published: August 2020

LGBTQ+ issues have recently caught enormous attention in Vietnam, and their existence in English as a foreign language (EFL) has been debated. This study explores eight Vietnamese EFL teachers’ attitudes toward incorporating LGBTQ+ content in their classrooms, primarily through the employment of the semistructured interview. It also examines their knowledge as well as experiences in queer issues, which serves as a foundation the teachers’ authority in introducing queer themes in the EFL environment. The results present the participants’ willingness to work on these issues in the EFL classroom despite their lack of knowledge and professional training.
Biological fixed‐film systems
Authors: Kim Eun‐Sik , Ha Jae‐Hoon , Choi Jeongdong
Published: August 2020

The technical papers published in 2019 regarding wastewater treatment and microbial films were classified into two categories: biofilm and biofilm reactors. The biofilm category includes biofilm formation, biofilm consortia, bacterial signals, biofouling, extracellular polymeric substances, and biofilm membrane bioreactors. The biofilm reactors category provides recent information on rotating biological contactors, fluidized‐bed biofilm reactors, integrated fixed‐film activated sludge, moving‐bed biofilm reactors, packed‐bed biofilm reactors, sequencing biofilm batch reactors, and trickling filters.
Implications of SARS‐CoV‐2 on current and future operation and management of wastewater systems
Authors: Maal‐Bared Rasha , Brisolara Kari , Munakata Naoko , Bibby Kyle , Gerba Charles , Sobsey Mark , Schaefer Scott , Swift Jay , Gary Lee , Sherchan Samendra , Babatola Akin , Bastian Robert , Olabode Lola , Reimers Robert , Rubin Albert
Published: August 2020

While researchers have acknowledged the potential role of environmental scientists, engineers, and industrial hygienists during this pandemic, the role of the water utility professional is often overlooked. The wastewater sector is critical to public health protection and employs collection and treatment system workers who perform tasks with high potential for exposures to biological agents. While various technical guidances and reports have initially provided direction to the water sector, the rapidly growing body of research publications necessitates the constant review of these papers and data synthesis. This paper presents the latest findings and highlights their implications from a water and wastewater utility operation and management perspective.

Practitioner points

Extrapolation from SARS‐CoV‐1 and MERS‐CoV, as well as other surrogates, has helped predicting SARS‐CoV‐2 behavior and risk management.

Data from treated wastewater effluent suggest that current processes are sufficient for SARS‐CoV‐2 control.

Scientific evidence supports the possibility of fecal–oral transmission for SARS‐CoV‐2.

Limited evidence supports the potential survival of infective SARS‐CoV‐2 on surfaces and in aerosols and the efficacy of control measures at reducing transmission.

Protective practices and PPE can protect workers from SARS‐CoV‐2 and other pathogens found in wastewater.
The defluorination of perfluorooctanoic acid by different vacuum ultraviolet systems in the solution
Authors: Li Yuanhao , Lin Qiufeng , Li Cong , Weiguo Zijian , Xu Luo , Zhang Kejia
Published: August 2020

Perfluorooctanoic acid (PFOA) is one kind of persistent organic pollutants that is often detected in water. In recent years, the effective degradation technologies of PFOA have attracted widespread attentions. Thus, in this study, the defluorination efficiency of PFOA in different systems (i.e., ultraviolet (UV), vacuum ultraviolet (VUV), vacuum ultraviolet/persulfate (VUV/PS) and vacuum ultraviolet/residual chlorine (VUV/RC)) was evaluated. Moreover, the different impact factors (i.e., the initial concentrations of persulfate and PFOA, temperature, anions, and initial pH values) on PFOA degradation by VUV/PS system were investigated. The results showed that VUV system was more effective than UV system for PFOA defluorination. VUV system combined with persulfate would further enhance the defluorination efficiency while residual chlorine would decrease it. In VUV/PS system, the defluorination efficiency of PFOA was the best as the molar ratio of PFOA and persulfate at 1:60. Moreover, higher temperature, lower initial PFOA concentration, and acid condition were favorable for the defluorination of PFOA. Under the different influence factors, the defluorination efficiency of PFOA fitted well to the first‐order reaction kinetic model. When the temperature was range from 20°C to 40°C, the value of activation energy was 8.73 kJ/mol. Besides, the inhibition effect of three kinds of anions on PFOA defluorination followed the order:  > Cl− > .

Practitioner points

The defluorination efficiency of perfluorooctanoic acid (PFOA) in water by different VUV systems was compared.

VUV system is more effective than UV system for PFOA defluorination.

Persulfate will enhance the defluorination efficiency by VUV system.

Hypochlorite will decrease the defluorination efficiency by VUV system.
Identification and associated hazards of clandestine drug laboratories
Authors: Norman Keith , Ciesielski Austin L. , Wagner Jarrad R.
Published: August 2020

The production of illicit drugs at clandestine laboratory operations is a world‐wide problem with many associated public health hazards. This review describes many laboratory types that might be encountered by the clandestine laboratory response personnel, describing the materials and processes associated with different clandestine laboratories to aid in awareness and hazard identification. Clandestine laboratories generally create products according to market forces, including the end‐user expectations with regard to product appearance (e.g., as solid or liquid, in powder or tablet formulation) and potency. The clandestine laboratories use different materials, and processes depending on the laboratory's access to precursors, their ability to produce quantities sufficient to meet market demands, and also their ability to circumvent local, national and international laws and regulations. The information presented here is aimed at both laboratory‐based scientists and analysts who have to understand the classical methods for production, which are still used, and consider novel methods using alternative precursors. It is important to be cognizant of the emerging drugs and drug analogues, how these are considered under the law, and how they can be safely collected for analysis. Clandestine laboratory responders must consider the information presented here from the perspective of the risks associated with the drugs, precursors, waste materials and equipment. As clandestine laboratories and drug markets are constantly evolving, responders need to consistently pursue ongoing education, research, and collaboration with the constant review and assessment of the emerging drugs and precursors seized during operations and reported on regional and international forums.

This article is categorized under:

Forensic Chemistry and Trace Evidence > Controlled and Emerging Drug Compounds

Toxicology > Drug Analysis

Crime Scene Investigation > Crime Scene Examination
Elliptic lift of the Shiraishi function as a non-stationary double-elliptic function
Authors: Awata Hidetoshi , Kanno Hiroaki , Mironov Andrei , Morozov Alexei
Published: August 2020

Abstract

As a development of [1], we note that the ordinary Shiraishi functions have an insufficient number of parameters to describe generic eigenfunctions of double elliptic system (Dell). The lacking parameter can be provided by substituting elliptic instead of the ordinary Gamma functions in the coefficients of the series. These new functions (ELS-functions) are conjectured to be functions governed by compactified DIM networks which can simultaneously play the three roles: solutions to non-stationary Dell equations, Dell conformal blocks with the degenerate field (surface operator) insertion, and the corresponding instanton sums in 6dSUSY gauge theories with adjoint matter. We describe the basics of the corresponding construction and make further conjectures about the various limits and dualities which need to be checked to make a precise statement about the Dell description by double-periodic network models with DIM symmetry. We also demonstrate that the ELS-functions provide symmetric polynomials, which are an elliptic generalization of Macdonald ones, and compute the generation function of the elliptic genera of the affine Laumon spaces. In the particular U(1) case, we find an explicit plethystic formula for the 6dpartition function, which is a non-trivial elliptic generalization of the (q, t) Nekrasov-Okounkov formula from 5d.
Flavour symmetries in the SMEFT
Authors: Faroughy Darius A. , Isidori Gino , Wilsch Felix , Yamamoto Kei
Published: August 2020

Abstract

We analyse how U(3)5 and U(2)5 flavour symmetries act on the Standard Model Effective Field Theory, providing an organising principle to classify the large number of dimension-six operators involving fermion fields. A detailed counting of such operators, at different order in the breaking terms of both these symmetries, is presented. A brief discussion about possible deviations from these two reference cases, and a simple example of the usefulness of this classification scheme for high-pT analyses at the LHC, are also presented.
Extended approach to the lateral tibial plateau with central meniscal subluxation in fracture repair: feasibility and first clinical and radiographic results
Authors: Korthaus Alexander , Ballhause Tobias Malte , Kolb Jan-Philipp , Krause Matthias , Frosch Karl-Heinz , Hartel Maximilian J.
Published: August 2020

Purpose

Anatomic reduction in tibial plateau fractures remains to be demanding. For further visualisation of and approach to the joint surface an extended lateral approach using a lateral femoral epicondyle osteotomy and subluxation of the lateral meniscus was recently described. First clinical and radiographic mid-term results of this technique are presented in this feasibility study.

Method

Ten complex tibial plateau fractures treated with extended lateral approach and lateral meniscal subluxation were prospectively analysed. Clinical and radiographic results were objectified according to the Rasmussen scores.

Results

After a median follow-up of 8.6 (IQR 4.3) months good to excellent clinical and radiographic results were noted. The clinical Rasmussen Score showed a median of 25 (IQR 2.8) and radiographic a median of 17 (IQR 2.0) points.

Conclusion

Good to excellent clinical and radiological scores were obtained after using an extended lateral approach with lateral femoral epicondyle osteotomy and central meniscus subluxation. No approach specific complications could be observed.
A systematic investigation into the effect of fibrillar microstructures on the settlement and attachment strength of the bay barnacle Balanus improvisus under natural conditions
Authors: Petersen Dennis S. , Schultz Marika , Gorb Stanislav N. , Heepe Lars
Published: August 2020

Barnacles are one of the most prominent hardfouling organisms in the marine environment. They are able to adhere efficiently to nearly every surface underwater including artificial ones like ship hulls and maritime installations. This overgrowing can lead to huge economical costs. Previous studies have shown that specific microstructure types including micropillars can reduce the initial settlement of barnacles. However, it is not clear how adult barnacles are influenced by microstructured surfaces and whether microstructures can even decrease the resulting adhesion strength of them under natural conditions. Therefore, the aim of this study was to systematically investigate the influence of height, diameter, aspect ratio and flexibility of fibrillar microstructures made from polydimethylsiloxane (PDMS) on initial settlement of barnacles as well as the permanent attachment of adult ones. Micropillars with three different heights (50 µm, 100 µm, 200 µm) and two different diameters (25 µm, 50 µm) were exposed to the Baltic Sea for 12 weeks. On a weekly basis, all barnacles (Balanus [= Amphibalanus] improvisus) were tracked individually to calculate the release-to-settlement ratio and to capture the average attachment duration prior to detachment. The results have shown that with increasing height, both initial settlement and fouling density development were reduced. An increase of diameter showed a similar relationship but at a much smaller scale. All tested microstructures decreased the detachment rates of barnacles from the surface compared to a flat PDMS control. However, they appear to complicate the development of a strong adhesive joint in the young adult phase. Some grade of flexibility in the microstructures appeared to increase the fouling retention. The results shed light in the interaction between adult barnacle adhesion and microstructures and may help in the development of new antifouling technologies.
Deposition, morphology and functional properties of layers based on DLC:Si and DLC:N on polyurethane
Authors: Kyzioł Karol , Jabłoński Piotr , Niemiec Wiktor , Prażuch Janusz , Kottfer Daniel , Łętocha Aneta , Kaczmarek Łukasz
Published: August 2020

DLC:Si and DLC:N (diamond-like carbons doped with Si or N) functional layers in different configurations are deposited on polyurethane (PU) for bioengineering applications using CCP (capacitively coupled plasma) discharge generated in the PE CVD (plasma-enhanced chemical vapor deposition) system. Scanning electron microscopy (SEM) observations show that the obtained single and multilayers are continuous and well adherent to the substrates, but they differ in surface morphologies. DLC:Si layers form granular-like outer surfaces, while DLC:N ones a mosaic structure of plain areas. Topography analyses by atomic force microscopy (AFM) and optical profilometry reveal that Si-doped layers are characterized by significantly higher surface roughness (Ra ca. 5 nm) in comparison to N-doped layers (Ra ca. 0.3 nm) and also higher values of profile roughness parameter Rz (up to 32 μm vs. about 13 μm). Energy-dispersive X-ray spectroscopy (EDS) analysis indicates the homogenous chemical composition of the layers. DLC:N layers, are characterized by significantly higher polar component of surface free energy (up to ca. 5.0 mJ/m2). DLC:Si layers exhibit higher values of diiodomethane contact angle (up to ca. 90°) compared with DLC:N layers (up to ca. 55°). The attenuated total reflectance Fourier transform infrared spectroscopic measurements (ATR-FTIR) of the layers reveal that the addition of silicon to the DLC structure increases the content of terminal CHn bonds (n = 1, 2, 3) as well as beneficial Si–H and Si–CHn bonds, which significantly reduce the internal stresses in the layers. Both DLC:Si and DLC:N layers exhibit no cytotoxic effects using the human osteoblast-like cell line and human keratinocytes.
Safety and efficacy of superior calyceal access versus inferior calyceal access for pelvic and/or lower calyceal renal calculi- a prospective observational comparative study
Authors: Amaresh M. , Hegde P. , Chawla A. , de la Rosette J. J. M. C. H. , Laguna M. P. , Kriplani A.
Published: August 2020

Objective

To compare efficacy and safety between superior calyceal access and inferior calyceal access for pelvic and/or lower calyceal renal stones.

Methods

Consecutive patients presenting with Pelvic and/or inferior calyceal renal calculi were allocated to the superior calyceal access (group 1) or inferior calyceal access (group 2) treatment arm. Allocation of treatment access was based on the surgeon’s preference. Variables studied included stone free rate, operating time, intraoperative and postoperative complications. Statistical analysis was executed using SPSS, Version 16.0. The statistical significance was evaluated at 5% level of significance (p value < 0.05).

Results

Between July 2018 and February 2019, 63 patients were included in each group. The percutaneous inserted guidewire entered the ureter in 92% in group1 and 74.6% in group 2 (p = 0.034). Stone fragments migrated to the middle calyx in 3.2% in group1 and 9.5% in group 2 (p = 0.033). A second puncture was required in one patient in group 1 and in 5 patients in group 2 (p = 0.04). The operative duration (minutes) was 13.46 ± 1.09 in the group 1 while 16.58 ± 1.44 in the group 2 (p = 0.002). Thoracic complications (hydropneumothorax) occurred to 2 patients in superior calyceal access group managed with intercostal tube drainage (p = 0.243).Post operatively blood transfusion was required in two patients in group 2 (p = 0.169). Angioembolization was done in one patient among the inferior calyceal access approach (p = 0.683). Complete stone clearance assessed at 3 months was 96.8% in group 1 and 85.7% in group 2 (p = 0.046).

Conclusions

Superior calyceal access is a safe and most efficacious in terms of achieving complete stone clearance rate with reduced operative time, minimal blood loss, less need for a second puncture and auxiliary procedures at minimal complications.

Study registration

Clinical trials registry – INDIA; CTRI/2018/07/014,687.
Matrix metalloproteinase-9 in relation to patients with complications after colorectal surgery: a systematic review
Authors: Edomskis Pim , Goudberg Max R. , Sparreboom Cloë L. , Menon Anand G. , Wolthuis Albert M. , D’Hoore Andre , Lange Johan F.
Published: August 2020

Purpose

Anastomotic leakage (AL) is the most severe complication following colorectal resection and is associated with increased mortality. The main group of enzymes responsible for collagen and protein degradation in the extracellular matrix is matrix metalloproteinases. The literature is conflicting regarding anastomotic leakage and the degradation of extracellular collagen by matrix metalloproteinase-9 (MMP-9). In this systematic review, the possible correlation between anastomotic leakage after colorectal surgery and MMP-9 activity is investigated.

Methods

Embase, MEDLINE, Cochrane, and Web of Science databases were searched up to 3 February 2020. All published articles that reported on the relationship between MMP-9 and anastomotic leakage were selected. Both human and animal studies were found eligible. The correlation between MMP-9 expression and anastomotic leakage after colorectal surgery.

Results

Seven human studies and five animal studies were included for analysis. The human studies were subdivided into those assessing MMP-9 in peritoneal drain fluid, intestinal biopsies, and blood samples. Five out of seven human studies reported elevated levels of MMP-9 in patients with anastomotic leakage on different postoperative moments. The animal studies demonstrated that MMP-9 activity was highest in the direct vicinity of an anastomosis. Moreover, MMP-9 activity was significantly reduced in areas further proximally and distally from the anastomosis and was nearly or completely absent in uninjured tissue.

Conclusion

Current literature shows some relation between MMP-9 activity and colorectal AL, but the evidence is inconsistent. Innovative techniques should further investigate the value of MMP-9 as a clinical biomarker for early detection, prevention, or treatment of AL.
Acute radial head replacement with bipolar prostheses: midterm results
Authors: Nosenzo Alessandro , Galavotti Cristina , Menozzi Margherita , Garzia Alice , Pogliacomi Francesco , Calderazzi Filippo
Published: August 2020

In irreparable radial head fractures, especially if primary stabilizers of the elbow are damaged, the prosthetic replacement prevents instability and stiffness. Concerns have arisen over the use of bipolar press-fit prostheses due to the frequent finding of osteolysis and the risk of instability if compared to monopolar implants. Our aim was to assess midterm clinical and radiological outcomes of bipolar implants and the influence of osteolysis on proximal pain. Seventeen patients with irreparable fractures of the radial head, treated in acute with the same prosthetic model (rHEAD recon SBI/Stryker) between January 2015 and December 2018, were enrolled. Clinical assessment was performed using MEPS and DASH scores; a radiographic study was done to identify heterotopic ossifications and periprosthetic osteolysis. Outcomes at the last follow-up, according to MEPS, were excellent in 10 cases, good in 5 and fair in 2; none of the patients had severe pain or instability. In 3 cases, it was necessary to remove the implant, mainly because of early loosening. Radiological findings of osteolysis were detected in 9 cases, but no statistical correlation was found with MEPS and proximal pain. The use of bipolar implants is reliable if an accurate repair of ligament tears is performed and provides a good stability. Nevertheless, the risk of early aseptic loosening in uncemented implants is not negligible, and the follow-up of the patient must be strict. Late osteolysis does not seem to have clinical relevance, but further prospective studies are necessary to clarify this topic.
Log end face image and stem tapering indicate maximum bow height on Norway spruce bottom logs
Authors: Raatevaara Antti , Korpunen Heikki , Mäkinen Harri , Uusitalo Jori
Published: August 2020

In cut-to-length logging, the harvester operator adjusts the bucking in accordance with visible defects on processed stems. Some of the defects, such as a sweep on the bottom of the stem, decrease the yield and quality of sawn products and are difficult for the operator to notice. Detecting the defects with improved sensors would support the operator in his qualitative decision-making and increase value recovery of logging. Predicting the maximum bow height of the bottom log in Norway spruce (Picea abies (L.) Karst.) with log end face image and stem taper was investigated with two modelling approaches. A total of 101 stems were selected from five clear-cut stands in southern Finland. The stems were crosscut and taper measured, and the butt ends of the bottom logs were photographed. The stem diameter, out-of-roundness, and pith eccentricity were measured from the images while the max. bow height was measured by a 3D log scanner at a sawmill. The bottom logs with an eccentric pith had higher max. bow height. In addition, a highly conical bottom part of the stem was more common on the bottom logs with a large max. bow height. Applying both log end face image and stem taper measurements gave the best model fit and detection accuracy (76%) for bottom logs with a large max. bow height. The results indicate that the log end face image and stem taper measurements can be utilised to aid harvester operator in deciding an optimised length for logs according to the bow height.
The effects of culture on mathematics lessons: an international comparative study of a collaboratively designed lesson
Authors: Clivaz Stéphane , Miyakawa Takeshi
Published: August 2020

This paper reports the results of an international comparative study conducted in Switzerland and Japan of an elementary school mathematics lesson. The principal aim of the study was to advance understanding of the cultural specificities of a mathematics lesson in its totality using concrete examples of lesson design and implementation and of how cultural factors within and beyond the classroom/school shape and produce mathematics lessons in a particular country. We analysed two Grade 4 mathematics lessons designed and implemented in Switzerland and Japan by pre-service teachers in the context of a project-based international exchange programme. The lesson, initially designed collaboratively by the pre-service teachers of the two countries, was ultimately realised in different ways in each country. Specifically, we found differences between the Japanese and Swiss lessons in the structure of the lesson and validation of solutions. To elucidate these differences and identify the cultural factors that yield them, we analysed the resources developed and used during lesson design and implementation (lesson plans, official documents, and textbooks). Furthermore, we discuss three aspects of mathematics lessons that account for the main characteristics of each lesson: collective or individualistic teaching and learning, problem-solving lessons, and distance between theory and practice.
On the need of preserving order of data when validating within-project defect classifiers
Authors: Falessi Davide , Huang Jacky , Narayana Likhita , Thai Jennifer Fong , Turhan Burak
Published: August 2020

We are in the shoes of a practitioner who uses previous project releases’ data to predict which classes of the current release are defect-prone. In this scenario, the practitioner would like to use the most accurate classifier among the many available ones. A validation technique, hereinafter “technique”, defines how to measure the prediction accuracy of a classifier. Several previous research efforts analyzed several techniques. However, no previous study compared validation techniques in the within-project across-release class-level context or considered techniques that preserve the order of data. In this paper, we investigate which technique recommends the most accurate classifier. We use the last release of a project as the ground truth to evaluate the classifier’s accuracy and hence the ability of a technique to recommend an accurate classifier. We consider nine classifiers, two industry and 13 open projects, and three validation techniques: namely 10-fold cross-validation (i.e., the most used technique), bootstrap (i.e., the recommended technique), and walk-forward (i.e., a technique preserving the order of data). Our results show that: 1) classifiers differ in accuracy in all datasets regardless of their entity per value, 2) walk-forward outperforms both 10-fold cross-validation and bootstrap statistically in all three accuracy metrics: AUC of the selected classifier, bias and absolute bias, 3) surprisingly, all techniques resulted to be more prone to overestimate than to underestimate the performances of classifiers, and 3) the defect rate resulted in changing between the second and first half in both industry projects and 83% of open-source datasets. This study recommends the use of techniques that preserve the order of data such as walk-forward over 10-fold cross-validation and bootstrap in the within-project across-release class-level context given the above empirical results and that walk-forward is by nature more simple, inexpensive, and stable than the other two techniques.
Assessing livelihood-ecosystem interdependencies and natural resource governance in a tribally controlled region of India’s north-eastern middle Himalayas
Authors: Everard Mark , Kataria Gaurav , Kumar Smita , Gupta Nishikant
Published: August 2020

Mountains host high biological and cultural diversity, generating ecosystem services beneficial over multiple geographical scales but suffering significant vulnerabilities. A case study in Lileng village (Arunachal Pradesh, Indian north-east Himalayas) explored linkages between a community with protected tribal rights and the forest and river ecosystems within which they are situated. Evidence was gathered through interviews and literature review about ecosystem service benefits, using the Rapid Assessment of Wetland Ecosystem Services approach. Subsequent analysis using the social, technological, environmental, economic, political framework found close, synergistic relationships between local people and the ecosystems for which they have protected tribal rights. Authoritative local governance arrangements prioritise community subsistence needs, limiting the influence of external state government and private actors on natural resource exploitation. Further sustainable economic development could stem from recognition of the value of ecosystem services produced by intact and functional habitats, and the potential for development of ‘payment for ecosystem services’ markets in addition to ecotourism and cultural tourism. Low food sufficiency and poverty observed in a previous study conducted in Uttarakhand state of the central Indian Middle Himalayas, principal drivers of out-migration and gender/age inequalities, were not evident in Lileng or surrounding areas, apparently linked to tribal rights and authoritative local governance in Arunachal Pradesh leading to greater resource security. Better understanding of ecosystem–community relationships in areas with protected tribal rights can highlight sustainable policies and practices that may be translated into wider geo-political areas, especially in the wake of projected climate change stresses.
Photometry of exoplanetary transits at Osservatorio Polifunzionale del Chianti
Authors: Naponiello L. , Betti L. , Biagini A. , Focardi M. , Papini E. , Stanga R. , Trisciani D. , Agostini M. , Noce V. , Fini L. , Pace E.
Published: August 2020

In this paper we report the observations of HD189733b, Kepler-41b, Kepler-42b, GJ 436b, WASP-77ab, HAT-P-32b and EPIC 211818569 as measured at the Osservatorio Polifunzionale del Chianti, a new astro-nomical site in Italy. Commissioning observing runs have been done in order to test capabilities, systematics and limits of the system and to improve its accuracy. For this purpose, a software algorithm has been developed to estimate the differential photometric error of any transit observation, so that the integration time can be chosen to reach optimal signal-to-noise ratios, and to obtain a picture of what kind of transits this setup can reveal. Currently, the system is able to reach an accuracy of about 1 mmag and so it is ready for the much needed exoplanetary transit follow-up.
Direct electrochemical production of pseudo-binary Ti–Fe alloys from mixtures of synthetic rutile and iron(III) oxide
Authors: Graham Simon J. , Benson Lyndsey L. , Jackson Martin
Published: August 2020

Combining the FFC-Cambridge process with field-assisted sintering technology (FAST) allows for the realisation of an alternative, entirely solid-state, production route for a wide range of metals and alloys. For titanium, this could provide a route to produce alloys at a lower cost compared to the conventional Kroll-based route. Use of synthetic rutile instead of high purity TiO2 offers further potential cost savings, with previous studies reporting on the reduction of this feedstock via the FFC-Cambridge process. In this study, mixtures of synthetic rutile and iron oxide (Fe2O3) powders were co-reduced using the FFC-Cambridge process, directly producing titanium alloy powders. The powders were subsequently consolidated using FAST to generate homogeneous, pseudo-binary Ti–Fe alloys containing up to 9 wt.% Fe. The oxide mixture, reduced powders and bulk alloys were fully characterised to determine the microstructure and chemistry evolution during processing. Increasing Fe content led to greater β phase stabilisation but no TiFe intermetallic phase was observed in any of the consolidated alloys. Microhardness testing was performed for preliminary assessment of mechanical properties, with values between 330–400 Hv. Maximum hardness was measured in the alloy containing 5.15 wt.% Fe, thought due to the strengthening effect of fine α phase precipitation within the β grains. At higher Fe contents, there was sufficient β stabilisation to prevent α phase transformation on cooling, leading to a reduction in hardness despite a general increase from solid solution strengthening.
Resource Model Updating For Compositional Geometallurgical Variables
Authors: Prior Ángel , Tolosana-Delgado Raimon , van den Boogaart K. Gerald , Benndorf Jörg
Published: August 2020

In the field of mineral resources extraction, one main challenge is to meet production targets in terms of geometallurgical properties. These properties influence the processing of the ore and are often represented in resource modeling by coregionalized variables with a complex relationship between them. Valuable data are available about geometalurgical properties and their interaction with the beneficiation process given sensor technologies during production monitoring. The aim of this research is to update resource models as new observations become available. A popular method for updating is the ensemble Kalman filter. This method relies on Gaussian assumptions and uses a set of realizations of the simulated models to derive sample covariances that can propagate the uncertainty between real observations and simulated ones. Hence, the relationship among variables has a compositional nature, such that updating these models while keeping the compositional constraints is a practical requirement in order to improve the accuracy of the updated models. This paper presents an updating framework for compositional data based on ensemble Kalman filter which allows us to work with compositions that are transformed into a multivariate Gaussian space by log-ratio transformation and flow anamorphosis. This flow anamorphosis, transforms the distribution of the variables to joint normality while reasonably keeping the dependencies between components. Furthermore, the positiveness of those variables, after updating the simulated models, is satisfied. The method is implemented in a bauxite deposit, demonstrating the performance of the proposed approach.
Hydrothermal anomalies of the Earth's surface and crustal seismicity related to Ms8.0 Wenchuan EQ
Authors: Zheng Shuo , Qin Kai , Wu Lixin , An Yanfei , Yin Qifeng , Lai Chunkit
Published: August 2020

Hydrothermal anomalies related to the Ms8.0 Wenchuan earthquake (EQ) on May 12, 2009, have been widely reported. However, the reported anomalies have not been associated with multi-geosphere analysis, and space–time analysis with crustal seismicity is lacking. In this paper, the space–time variation of hydrothermal parameters, including soil moisture, soil temperature, near-surface relative humidity (RHsig995) and air temperature (TMPsfc), was first extracted and analyzed with the NCEP-FNL reanalysis dataset. The b-value (a seismic parameter from the Gutenberg–Richter law) was calculated and mapped to unravel the crustal stress and rock rupture. Our results reveal a similar time window for hydrothermal anomalies on April 20 and April 30, 2008, and these anomalies are mainly distributed along the southern and middle parts of the Longmenshan fault zone. The surface temperature anomalies lag behind the humidity anomalies, and the accelerating stress accumulation started since June 2007 and lasted for eight to nine months before the mainshock. The b-value mapping shows a segmented difference along strike of the Longmenshan fault, and that regional stress accumulated mainly in the southern parts of the F2 and F3 faults. We propose the occurrence of a complex coupling process led by crustal stress buildup before the Wenchuan EQ. The anomalies are concentrated in the southern part of the surface rupture zone. The prolonged crustal stress accumulation corresponds to the short intermittent hydrothermal response on the Earth’s surface before the Wenchuan EQ. Our findings reveal new hydrothermal anomalies in the Earth’s surface and atmosphere and explore direct link with seismogenic processes in the crust.
Potential Theory on Minimal Hypersurfaces II: Hardy Structures and Schrödinger Operators
Authors: Lohkamp Joachim
Published: August 2020

Area minimizing hypersurfaces and, more generally, almost minimizing hypersurfaces frequently occur in geometry, dynamics and physics. A central problem is that a general (almost) minimizing hypersurfaceHcontains a complicated singular set Σ. Nevertheless, we manage to develop a detailed potential theory onH∖Σ applicable to large classes of linear elliptic second order operators. We even get a fine control over their analysis near Σ. This is Part 2 of this two parts work.
How effectively do households insure food consumption and assets against funeral expenses? The case of urban Zimbabwe
Authors: Dafuleya Gift , Tregenna Fiona
Published: August 2020

In response to funeral expenses, which drastically affect household consumption, many families in developing countries enter into formal and/or informal funeral insurance arrangements. Using new household survey data collected in the city of Bulawayo, Zimbabwe, we investigate the effectiveness of these arrangements in insuring food consumption and household non-financial assets against funeral expenses. We find that informal funeral insurance, especially when combined with formal insurance, effectively insures household assets from funeral shocks. Households that own more than one item of the same asset prefer to sell assets rather than destabilise food consumption, in the event that funeral insurance is inadequate or not available. Households without multiple of the same asset prefer to retain their assets and destabilise food consumption. We also show that the funeral insurance of households in Bulawayo partially insures food consumption. Our findings suggest that households have a hierarchy of preferred coping strategies when they are either uninsured or not fully insured against shocks.
Measurement and Analysis of Heterogeneous Strain Fields in Uniaxial Tensile Tests for Boron Steel Under Hot Stamping Conditions
Authors: Zhang R. , Shao Z. , Lin J. , Dean T. A.
Published: August 2020

Background

A significant amount of uniaxial tensile tests has been carried out using Gleeble systems to investigate the viscoplastic deformation of boron steel (22MnB5) under hot stamping conditions. However, due to heat loss through the end clamps, a temperature gradient in the reduced parallel section of dog-bone shaped specimens is inevitable.

Objective

In the work reported in this paper, the effect of temperature gradient on measured outcomes is examined.

Methods

Uniaxial tensile tests on 1.5 mm thick boron steel specimens are carried out, under hot stamping conditions and strain fields are quantified using the digital image correlation (DIC) technique. The effect of gauge length on the properties of boron steel, as calculated from observed test results, is determined.

Results

Compared with the test at room temperature, a bell-shaped strain distribution occurs within the gauge length even before the appearance of the maximum load. Also, average strain within the gauge length, especially in the later stages, changes with gauge length within the investigated range, and thus, different engineering stress-strain curves and fracture strains are determined. In addition, normalized strain rate is significantly dependent on gauge length, which results in over 16% difference among the computed flow stresses by using a unified constitutive model.

Conclusions

The characterized properties of the material are dependent on gauge length and thus, a testing standard for measuring thermal-mechanical data of materials by using a Gleeble need to be defined.
Basalt fibers as functional additives in coating of textiles
Authors: Ruffen Carolin , Mahltig Boris
Published: August 2020

In the presented study, basalt fibers are used as additives in polymer coatings applied onto textiles substrates. As basalt fibers, short fibers with diameters of around 13 µm and with lengths in the range of 0.16–4 mm are used. As the textile substrate, a cotton fabric is used. The polymer coatings are based on acrylate or polyurethane. As a further coating additive, the silicate compound Aerosil is also evaluated. The realized coated materials are investigated by scanning electron microscopy (SEM) and by optical spectroscopy in arrangement of diffusive reflection and transmission. The optical spectra are recorded in a spectral range from 220 to 1400 nm. By these optical measurements, it is demonstrated that the optical properties for UV-light, visible light and near infrared light are influenced by the basalt-containing coatings. The transmission for UV-light is drastically reduced. It is possible to decrease the transmission for infrared light drastically by use of these coating while the IR-reflectance stays on a significant level. In future perspective, these types of coatings could be used as protection against both UV- and IR-light. The surface topography of realized coatings is dominated by the applied basalt fibers. In the case of medium or high basalt fiber concentration, a parallel orientation of some basalt fibers occurs. This type of parallel arrangement could be used in future perspective for different types of applications, e.g., the development of new filter materials.