bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of Bacteria in the Development of Colorectal Cancer
Authors: Thomas Ryan M.
Published: January 2023

Colorectal cancer (CRC) is the second leading cause of cancer-related death in the United States. Once limited to older populations, the incidence of CRC in patients under the age of 50 years is increasing and the etiology for this is uncertain. One hypothesis lies on the impact of the intestinal microbiome. The intestinal microbiome, composed primarily of bacteria but also viruses, fungi, and archaea, has been shown to regulate CRC development and progression both in vitro and in vivo. In this review, the role and intersection of the bacterial microbiome in various stages of clinical CRC development and management are discussed beginning with CRC screening. Various mechanisms whereby the microbiome has been shown to modulate CRC development including the influence of diet on the microbiome, bacterial-induced injury to the colonic epithelium, bacterial-produced toxins, and alteration of normal cancer immunosurveillance by the microbiome are discussed. Finally, the influence of microbiome on the response of CRC to treatment is discussed while highlighting ongoing clinical trials. The complexities of the microbiome and its role in CRC development and progression have become apparent and will require ongoing commitment to translate laboratory findings into meaningful clinical results that will aid more than 150,000 patients that develop CRC every year.
Hyperglycemia in the Perioperative Period
Authors: Shuford Rebecca , Miller-Ocuin Jennifer L.
Published: January 2023

Perioperative hyperglycemia is a risk factor in surgical patients. Complications, including infection and mortality, are associated with hyperglycemia in both diabetic and nondiabetic patients. Stress hyperglycemia results in a state of insulin resistance. Insulin administration has been shown to reduce the complications associated with hyperglycemia. Glycemic targets provide goals for individualized treatment of hyperglycemia in surgical patients in the preoperative, intraoperative, and postoperative periods.
The mobilizing effects of political media consumption among external voters
Authors: Himmelroos Staffan , von Schoultz Åsa
Published: January 2023

This study examines political media consumption among non-resident citizens, and whether following politics in traditional and social media in their country of residence and origin has a mobilizing effect on voting in origin-country elections. The topic of our study is inspired by the trend towards increased enfranchisement of external citizens, improved methods for participation from abroad, and the transformation of the media landscape with enhanced possibilities for external voters to follow politics in their country of origin. Based on a survey directed towards a stratified random sample of Finnish external citizens in 15 countries, we find that politically oriented media consumption in the country of origin substantially increases the likelihood of participating in origin-country elections and that this effect holds for traditional media channels as well as for social media. A corresponding mobilizing effect is, however, not found for following politics in the country of residence. This demonstrates the value of relevant information for political participation.
Quantum dispersion properties of eigenmodes in semiconductor nanotubes with dielectric filling in dc magnetic field
Authors: Averkov Yu. O. , Prokopenko Yu. V. , Yakovenko V. M. , Yampol’skii V. A.
Published: January 2023

Dispersion properties of electromagnetic eigenmodes in a semiconductor nanotube (with quadratic electron dispersion law) filled by a nonmagnetic dielectric and placed in a coaxial dc magnetic field are studied theoretically. A new quantum electrodynamical phenomenon is predicted. Namely, it is shown that increase in the electron density n02D in the nanotube results in the appearance of new branches in the eigenmodes spectrum. These branches arise in a bifurcation manner at some critical values of n02D, when a new electron energy subzone starts to fill in. The number of branches monotonously increases with growth n02D and oscillates with increase in the number of magnetic flux quanta through the nanotube (i.e., a peculiar Aharonov–Bohm effect takes place). We also found that the dispersion curves have parts with anomalous dispersion. The analytical expression for electron energy loss due to the excitation of eigenmodes under the Cherenkov resonance condition is derived and numerically analyzed.
A first principle study of structural and electrical properties of novel Li2FeO3/Li2FeO2F Li-ion battery cathode material
Authors: Yousefi-Mashhour Hatef , Namiranian Afshin , Kalantarian Mohammad Mahdi
Published: January 2023

Li-ion battery cathode materials, namely Li2FeO3 and Li2FeO2F, are investigated using noble evaluation approaches for the electrical properties, assuming that the reacted-unreacted structure interface is acting as a semiconductor junction. The evaluations are done by calculating different methods of density functional theory, and consequently resulted in lattice parameters and their changes, structural properties, and also density of states (DOS) diagrams to assess electrical properties. The approach assigns a value for each evaluated cathode material and provides a semi-quantitative criterion in the matter of rate-capability for having a comparison between the materials. It also considers the configuration of the unreacted-reacted structures with respect to each other and also the electric field direction simultaneously. Results from structural data showed that evaluated cathode materials face a significant amount of cell volume decrease during the delithiation process, thus it is expected that it has a strong impact on their cyclability and lifetime. According to the rate-capability criterion values obtained from the DOS diagrams calculated via GGA+U and GGA, results show that the presence of the Fluorine element inside the structure can improve the rate-capability.
Quantum effects in silicon-germanium p-type heterostructures with quantum wells of different widths
Authors: Berkutov I. B. , Andrievskii V. V. , Beliayev E. Yu. , Kolesnichenko Yu. A.
Published: January 2023

The magneto-quantum and quantum interference effects in a two-dimensional gas of p-type charge carriers are studied for three quantum wells made of practically pure germanium in a Si0.6Ge0.4/Si0.2Ge0.8/Si0.6Ge0.4 heterostructure. The quantum well widths were 8 nm for sample I, 19.5 nm for sample II, and 25.6 nm for sample III. The dependences of resistance on the magnetic field for all samples exhibit Shubnikov–de Haas oscillations. Their analysis made it possible to calculate the kinetic characteristics of charge carriers for the cases of one (sample I) and two occupied subbands (samples II and III). In the region of weak magnetic fields (B < 0.1 T), the effect of weak localization of holes was revealed, which determines the negative magnetoresistance and the increase in resistance with decreasing temperature. The manifestation of the charge carriers interaction effect at various temperatures and magnetic fields is discovered and analyzed. A transition from the diffusion mode of manifestation of the quantum correction to the intermediate, and then to the ballistic mode is observed. In all regions, the behavior of the quantum correction due to the charge carriers interaction effect is in good agreement with modern theoretical predictions. The temperature dependences of the hole-phonon relaxation time are calculated. In weak magnetic fields, with an increase in the temperature of the 2D system, a transition from the “partial inelasticity” mode, characterized by the dependence τhph−1∝T2, to the small-angle scattering mode, described by the relation τhph−1∝T5, takes place. In stronger magnetic fields for samples with two occupied subbands, the dependence τhph−1∝T3was observed. Possible explanations for this dependence are presented.
Superconducting source and sensor of single bubbles to study nucleate boiling of liquid helium
Authors: Sivakov A. G. , Turutanov O. G. , Kruhlov S. A. , Krevsun A. V. , Pokhila A. S. , Kolinko A. E. , Bondarenko S. I. , Grajcar M.
Published: January 2023

Joule heat generated by resistive elements of cryogenic micro- and nanodevices often originates boiling of the cooling cryogenic liquids (helium, nitrogen). The article proposes an experimental method to explore the dynamics of the formation and development of a single vapor bubble in cryogenic liquid by sensing the temperature change of a superconducting thin-film microbridge being in the resistive state with single phase slip center or line. It serves both the source of heat for generating single bubbles and the surface temperature sensor due to its temperature-dependent excess current. The average bubble detachment rate and the average single bubble volume were experimentally determined for nucleate helium boiling. The obtained values are in good agreement with the data of other authors found in literature.
Pressure effects on magnetic properties of LaMnO3 and YMnO3
Authors: Panfilov A. S. , Grechnev G. E. , Pashchenko V. A. , Prabhakaran D.
Published: January 2023

The magnetic susceptibility χ of RMnO3 (R = La, Y) manganites was measured for paramagnetic phase as a function of the hydrostatic pressure P up to 2 kbar at some fixed temperature in the range from 78 to 300 K. A pronounced magnitude of the pressure effect dln χ/dP was found to be positive in sign for LaMnO3 and negative for YMnO3, both being strongly temperature dependent. Analysis of the experimental data, based on the Curie-Weiss behavior of χ(Τ), allowed to estimate the pressure derivative of the paramagnetic Curie temperature to be dΘ/dP = (0.25 ± 0.03) and −(2.4 ± 0.4) K/kbar for LaMnO3 and YMnO3, respectively.
Ultrashort channel chemical vapor deposited bilayer WS2 field-effect transistors
Authors: Shi Xinhang , Li Xuefei , Guo Qi , Zeng Min , Wang Xin , Wu Yanqing
Published: January 2023

Two-dimensional transition metal dichalcogenides (TMDs) are potential candidates for next generation channel materials owing to their atomically thin structure and high carrier mobility, which allow for the ultimate scaling of nanoelectronics. However, TMDs-based field-effect transistors are still far from delivering the expected performance, which is mainly attributed to their high contact resistance and low saturation velocity (vsat). In this work, we report high-performance short-channel WS2 transistors based on bandgap engineering. The bilayer WS2 channel not only shows a higher average field-effect mobility (μFE) than the monolayer channel but also exhibits excellent metal-Ohmic contact using a regular physical vapor deposition deposited Ni/Au contact, reducing the Rc value to a record low value of 0.38 kΩ · μm without any intentional doping. The bilayer WS2 device of the 80 nm channel exhibits a high on-state current of 346 μA/μm at Vds = 1 V, near-zero drain-induced barrier lowering, and a record high Ion/Ioff ratio over 109. Furthermore, a record high on-state current of 635 μA/μm at Vds = 1 V and a record high vsat of 3.8 × 106 cm/s have been achieved for a shorter 18 nm channel device, much higher than previous WS2 transistors. This work reveals the intrinsically robust nature of bilayer WS2 crystals with promising potential for integration with conventional fabrication processes.
Structural feature in dynamical processes accelerated transition state calculations
Authors: Cai Hongsheng , Liu Guoyuan , Qiu Peiqi , Luo Guangfu
Published: January 2023

Minimum energy path (MEP) search is a vital but often very time-consuming method to predict the transition states of versatile dynamic processes in chemistry, physics, and materials science. In this study, we reveal that the largely displaced atoms in the MEP structures maintain transient chemical bond lengths resembling those of the same type in the stable initial and final states. Based on this discovery, we propose an adaptive semirigid body approximation (ASBA) to construct a physically reasonable initial guess for the MEP structures, which can be further optimized by the nudged elastic band method. Examination of several distinct dynamical processes in bulk, on crystal surface, and through two-dimensional system shows that our transition state calculations based on the ASBA results are robust and significantly faster than those based on the popular linear interpolation and image-dependent pair potential methods.
Convolutional kernel with PrCaMnOx-based resistive random-access memory for neuromorphic image processing
Authors: Hong Eunryeong , Jeon Seonuk , Kim Nayeon , Kim Hyun Wook , Kang Heebum , Moon Kibong , Woo Jiyong
Published: January 2023

This paper investigated the conductance-state stability of TiN/PrCaMnOx (PCMO)-based resistive random-access memory (RRAM), which serves as a kernel weight element in convolutional neural networks (CNNs), to realize accurate feature extraction from images. On application of the initial forming process that actively drives more oxygen ions to form an interfacial layer between TiN and PCMO to RRAM devices with a high voltage of ±4 V, resistive switching behavior with a noticeable memory window was observed. However, the achieved conductance states continued to decrease during repeated cycling. The oxidation at the interface tended to occur thermodynamically, implying an increase in interfacial layer thickness. Considering the hardware implementation of the kernel weight matrix, with specifically assigned conductance values of the RRAM, state instability in the RRAM renders image edge detection difficult, eventually degrading the overall recognition accuracy of the CNN. Thus, we introduced an asymmetric programming voltage method, wherein a higher set voltage of −3 V than a reset voltage of +2.5 V can shift more oxygen ions back into PCMO. Consequently, when the RRAM devices programmed to different states were maintained without degradation in the 1 K cross-point array, eight clearly distinct weighted sum currents were demonstrated in the 3 × 1 subarray. Based on the measurement results, we performed feature extraction in CNN algorithms through MATLAB simulation, demonstrating input image edge detection with a high accuracy of 92%.
Heat transfer of thin flat heat pipes with gradually varied vapor–liquid channels
Authors: Peng Guohong , Zhang Zhikun , Wang Yaxin , Zhang Yanhui , Zhao Zhengang
Published: January 2023

The heat flow density is constantly increasing due to the growing demand for the integration and compaction of electronic devices. A sintered thin flat heat pipe (TFHP) is a typical device for managing the heat flux of highly integrated electronic circuits. Four different structures of the vapor–liquid flow channel architecture are designed in this work. Heat transfer performance tests of different TFHPs are carried out for different thermal powers. The surface temperature distribution and thermal resistance of the TFHP under different operating conditions are investigated. The experimental results show that the design of the vapor–liquid flow channel significantly impacts the TFHP’s heat transfer performance and that the wedge-shaped wick is better suited to the flow channel. The wedge-shaped wick has the lowest thermal resistance of 0.28 °C/W and the most elevated maximum thermal power of 22 W. The heat dispatch performance of the sintered wick TFHP is improved.
Highly compressible and thermal insulative conductive MXene/PEDOT:PSS@melamine foam for promising wearable piezoresistive sensor
Authors: Zhang Minyue , Yang Wenke , Wang Ziqi , Liu Hu , Yin Rui , Liu Chuntai , Shen Changyu
Published: January 2023

With the rapid development of intelligent wearable electronic devices, highly compressible porous piezoresistive sensors are in imperative demand. However, the robustness of conductive coating that affects the stability and durability of porous piezoresistive sensors still needs to be solved urgently. In this work, a flexible conductive MXene/PEDOT:PSS@Melamine foam (MPMF) piezoresistive sensor was designed and prepared by simply dip-coating it in MXene and PEDOT:PSS mixed solution. Here, foam skeleton was first treated with PDA to improve its hydrophilicity and enhance the interfacial interaction with the functional groups of MXene nanosheets. More importantly, the usage of PEDOT:PSS can fix the MXene nanosheets tightly and construct synergistic conductive network between them, obtaining stable, robust, and highly conductive coating. Based on the contact effect between the adjacent conductive skeleton, the prepared MPMF sensor displays excellent piezoresistive sensing performances, which includes a wide working range (up to 80% compression strain, 60 kPa pressure), high sensitivity (0.30 kPa−1 in the pressure range of 12–60 kPa), and stable sensing pattern over 1000 compression cycles. All these merits make the sensor capable of detecting various human motions and pressure/location distribution of different items when assembled into an electronic skin. In addition, excellent thermal insulation property under different temperature conditions was also observed for MPMF due to the existence of special porous structures, providing necessary thermal protection when served as a wearable sensor. This research provides a convenient, simple, and cost-effective method for the manufacture of high-performance porous piezoresistive sensor.
Brucellosis Surveillance and Control: A One Health Case Study
Authors: Zinsstag Jakob
Published: January 2023

Brucellosis is one of the world’s major zoonoses (

Dean
et al
., 2012a

). Human infection results mainly from direct contact with infected animals (often occupational exposure) or from the consumption of contaminated raw milk or dairy products (consumer exposure). Human brucellosis exposure can ultimately only be prevented by its elimination in animals. Control and elimination in the animal host are most effectively achieved by mass vaccination and, if possible, subsequent test-and-slaughter programmes (

Zinsstag
et al
., 2011

). Economic studies show that it is highly profitable for pastoral societies to eliminate brucellosis. The societal benefits are three times higher than the investment in the mass vaccination of livestock (

Roth
et al
., 2003

). Hence, brucellosis control is a landmark example of the benefits of a One Health approach to zoonoses control, when compared to focusing solely on public health. The most important causative agents are
Brucella melitensis
(sheep and goats),
Brucella abortus
(cattle),
B. suis
(pigs) and
B. canis
(dogs). Brucella are gram-negative coccobacillary bacteria with an intracellular predilection in the host. The main clinical feature in livestock is late-stage abortion (Figure
1
), at which time bacteria are excreted in high numbers. Brucella may be shed during prolonged periods in milk after the cessation of clinical signs. Brucellosis causes mainly a loss of fertility and a reduction of milk production in sheep, goats and cattle. Symptoms of the disease in people are highly variable. In general,
B. melitensis
causes a more severe illness, with less severe forms caused by
B. suis
and
B. abortus
. The main symptoms are fever, sweats, malaise, anorexia, headache, arthralgia, myalgia, backache and weight loss (

Dean
et al
., 2012b

). The bacteria can localize anywhere in the body. Two-thirds of the cases become chronic and the illness can continue for years if patients do not receive appropriate treatment (

Roth
et al
., 2003

). There is no or very rare human-to-human transmission of brucellosis. Acute human brucellosis without complications should be treated with a combination therapy of doxycycline-streptomycin or doxycycline-gentamicin. Focal forms often require prolonged treatment.

Swiss TPH logo

Information

This case study is extracted from Chapter 14 of Zinsstag
et al.
2015 (OH Book) and the Policy brief on the elimination of brucellosis in Central Asia.

© The Authors 2023
Higher Dimensional Camassa–Holm Equations
Authors: Lou S. Y. , Jia Man , Hao Xia-Zhi
Published: January 2023

Utilizing some conservation laws of the (1+1)-dimensional Camassa–Holm (CH) equation and/or its reciprocal forms, some (n+1)-dimensional CH equations for n ≥ 1 are constructed by a modified deformation algorithm. The Lax integrability can be proven by applying the same deformation algorithm to the Lax pair of the (1+1)-dimensional CH equation. A novel type of peakon solution is implicitly given and expressed by the LambertW function.
Observational constraints in accelerated emergent f(Q) gravity model
Authors: Shekh S H , Bouali A , Mustafa G , Pradhan A , Javed F
Published: January 2023

In this study, the non-metricity scalar Q, which characterizes the gravitational interaction, is used to analyze the Universe’s rapid expansion within the context of the f(Q) gravity theory. We suggest an emergent scale factor, which produces the deceleration parameter in redshift form which determines the solution of the field equations in the FLRW Universe. We evaluate the appropriate values of the model parameters by considering SNIa from Pantheon, CMB from Planck 2018, BAO, and 36 data points from Hubble datasets using Markov Chain Monte Carlo approach. The deceleration parameter’s development suggests that the Universe is moving from its deceleration phase into its acceleration phase. Furthermore, we analyze the statefinder (r, s) diagnostic parameter. We also use some different forms of f(Q) gravity models to study some other cosmological parameters, i.e.

f
(
Q
)
=

α

1

Q

,

f
(
Q
)
=

α

2

Q

m

and

f
(
Q
)
=

α

3

Q

m

+
Q

, where α
1, α
2, α
3 and m all are free model parameters. Finally, we concluded that all f(Q) models predict that at z = 0, Universe is in the phase of accelerating and behaves like the quintessence models and at

z
=
−
1

, approaches to ΛCDM models.
Effect of frequency on droplet actuation in reverse electrowetting
Authors: Wang Li-Ming , Zhao Rui , Liang Zhong-Cheng , Zhang Jian , Kou Song-Feng
Published: January 2023

In this work, a theoretical formula based on equivalent circuit model is proposed to describe the influence of frequency on the droplet actuation behavior in reverse electrowetting. To verify the theory, changes of droplet profile are monitored by charge coupled device (CCD) camera and simulated by COMSOL. It shows that the threshold voltage required for the droplet to start contracting inward increases firstly and then decreases with the increasing frequency. When the frequency is 1 kHz, the threshold voltage reaches the maximum value. Once the droplet begins to move inward, its contact angle increases with the working voltage. As for 4 kHz, the contact angle increases linearly from 60° to 154° when voltage ranges from 16 V to 50 V, while the droplet remained stationary when

U

< 16 V. The relative experimental results well accord with the theoretical prediction.
A new breast phantom suitable for digital mammography, contrast-enhanced digital mammography and digital breast tomosynthesis
Authors: Zhang Changsheng , Fu Jian
Published: January 2023

Our objective is to report a new breast phantom that provides the objective assessment for three types of clinical mammography, i.e. digital mammography (DM), contrast-enhanced digital mammography (CEDM), and digital breast tomosynthesis (DBT). The tissue-equivalent materials are used to represent the corresponding tissue, and the layer-by-layer structure with separate regions is designed for image quality assessment of different mammography modes. For DM imaging, substitutes for microcalcifications and fibroglandular tissue of different sizes are used to simulate the conventional breast. For CEDM imaging, the tumor module that can be injected with imaging contrast agents is adopted to distinguish normal tissue and diseased tissue in the dense breast. For DBT imaging, the overlapping breast mass module with multiple layers is designed to perform the layer-by-layer imaging of overlapping tissue. In addition, the quantitative assessment module of image quality is designed based on contrast-to-noise ratio, modulation transfer function and artifact spread function. This phantom allows image quality to be evaluated objectively for three different types of the clinical mammography, while it provides an effective tool for optimizing the dose-image quality relationship of patients.
Low-energy scatterings and pseudopotential of polarized quadrupoles
Authors: Deng Fulin , Zhang Wenxian , Yi Su
Published: January 2023

We investigate the low-energy scattering properties of two identical particles interacting via the polarized quadrupolar interaction. It is shown that a series of s- and p-wave resonances appear for identical bosons and fermions, respectively, as the strength of the quadrupolar interaction increases. Interestingly, scattering resonances also appear on the generalized scattering length corresponding to the coupling between the s and d waves. This observation inspires us to propose a new pseudopotential for the quadrupolar interaction. We also explore the bound-state properties of two particles in both free space and harmonic traps.
A variable refractive index sensor based on epsilon-near-zero spatial selection structure and its potential in biological detection
Authors: Wan Bao-Fei , Ye Hai-Ning , Zhang Dan , Zhang Haifeng
Published: January 2023

In this paper, a spatially selective (SS) structure is investigated through the critical jump characteristic when the permittivity of the epsilon-negative (ENG) materials approaches zero. In the range where the incident frequency of the TE wave is 5.1–5.6 c d−1 and that of the TM wave is 5.0–5.7 c d−1, the transmittance exceeds 0.85 and the squareness factor (SF) surpasses 0.9. By adjusting the electronic plasma frequency to affect the position of epsilon-near-zero (ENZ) frequency, a wide-angle control of the SS characteristic extent is produced. Using the fragility of the critical angle to the background analyte medium, a variable refractive index sensor is proposed. When the electronic plasma frequency is continuously altered, the analyte with the measurement range of 1.1–1.3, 1.3–1.5, 1.5–1.7, or 1.7–1.9 can be detected. The corresponding sensitivity is 57.1 degrees/RIU, 48.8 degrees/RIU, 40.0 degrees/RIU, or 32.8 degrees/RIU. The elongation in the thickness of ENG materials contributes to the improvement of the SF, executing the discrimination of Vibrio cholera, E. coli, and Shigella flexneri. The effects of losses on device performance are also briefly considered. Different from previous studies, the proposed SS selective structure adopts a new ENZ mechanism, can simplify the design of the structure to a certain extent and has a possibility in the design of highly sensitive sensors.
Time-extended inductive tokamak discharges with differentially-tilted toroidal field coils
Authors: Gatto R. , Bombarda F. , Gabriellini S. , Murgo S. , Zotta V.K.
Published: January 2023

The strong toroidal magnetic field required for plasma confinement in tokamaks is generated by a set of D-shaped coils lying equidistant on meridian planes toroidally located around the central axis of the device. A major technological challenge tied to this configuration is represented by the large Lorentz force acting on the coils and arising from the interaction of the coils’ currents with the magnetic field generated by the coil system itself. As this force is given by the cross product of the coil current and the magnetic field, various kinds of coil geometry modification have been proposed to alleviate this problem, from an inclination of the entire coil in order to maintain its planarity, to azimuthal tilting of all, or parts of, the coil profile. When the inner legs of the coils are tilted, apart from a reduction of the electromagnetic forces, a solenoid-like structure is formed which introduces additional magnetic flux linked to the plasma. Considering compact, high field devices, it is shown that when this additional flux is exploited, totally or in part, to ramp up the plasma current, the discharge time can be extended by a significant amount without resorting to noninductive current drive systems. Operational scenarios with inner-leg-tilted toroidal field coils are presented.
Stability of ground state degeneracy to long-range interactions
Authors: Lapa Matthew F , Levin Michael
Published: January 2023

We show that some gapped quantum many-body systems have a ground state degeneracy that is stable to long-range (e.g. power-law) perturbations, in the sense that any ground state energy splitting induced by such perturbations is exponentially small in the system size. More specifically, we consider an Ising symmetry-breaking Hamiltonian with several exactly degenerate ground states and an energy gap, and we then perturb the system with Ising symmetric long-range interactions. For these models we prove (a) the stability of the gap, and (b) that the residual splitting of the low-energy states below the gap is exponentially small in the system size. Our proof relies on a convergent polymer expansion that is adapted to handle the long-range interactions in our model. We also discuss applications of our result to several models of physical interest, including the Kitaev p-wave wire model perturbed by power-law density–density interactions with an exponent greater than 1.
The Solution of Structure Constrained Problem Using Decomposition Method
Authors: Cipta Hendra , Suwilo Saib , Sutarman  , Mawengkang Herman
Published: January 2023

In practice, linear programming problems may have many variables and constraints. The decomposition method can be applied to problems with some special structure in order to obtain the solution. This method allows determining the optimal solution by decomposing structure constraints into several parts of the problem, then completing the parts of the problem independently. The purpose of this study is to provide on optimal solution to large scale constraints problem by decomposition method.
Comparison of completion of VAM, TCOM-SUM Transportation problems with Stepping Stone to Determine optimal solutions
Authors: Amisah Lubis Loria , Mardiningsih
Published: January 2023

This research discusses to optimize the path and find out the distribution of minimum transportation costs using the VAM (Vogel’s Approximation Method) method, TOCM-SUM is then optimized through the stepping stone test. The VAM method is one of the methods of preparing a initial feasible solution by Determining the distribution table allocation to the cell that has the least cost. TOCM-SUM method to find a suitable initial solution of the transportation problem. The optimal stepping stone test aims to test the initial solution table by calculating the cost of empty cells that are passed by the stepping stone path.
Purification of glycerol from biodiesel by-product by using kitchen vinegar
Authors: Rizky Y , Panggabean S , Sigalingging R , Raju
Published: January 2023

Indonesia is a country that produces large amounts of palm oil. Oil palm plantations are often found in Sumatra and Kalimantan. Palm oil is usually used as a raw material for making cooking oil. Apart from that, it can be used as a raw material for biodiesel production from vegetable oil taken from palm oil. The production of biodiesel from palm cooking oil produces a by-product in the form of glycerol, where the glycerol is still in the form of crude glycerol which cannot be utilized. Glycerol purification is carried out by the method of acidification and evaporation to remove the KOH catalyst and methanol that are still present in the crude glycerol. The acid used was 2 ml of kitchen vinegar and was carried out 3 times. The purpose of this study was to obtain glycerol and water content. The results of this study showed that the highest glycerol content was 83.47%, the lowest water content was 1.83%, the lowest pH was 12.00 and the color of glycerol was blackish brown.
Regeneration of spent bleaching earth using microwave assisted extraction method with hexane as solvent for the bleaching of crude palm oil
Authors: Nugraha  , Iriany  , Misran E
Published: January 2023

One of the wastes in palm oil mills is spent bleaching earth (SBE) which is produced from the bleaching process. In landfills, SBE can produce unpleasant odors, pollute the land and can be quickly oxidized and spontaneously auto ignition occurs. SBE consists of residual oil, phospholipids and several minor components resulting from the bleaching process. Microwave-assisted extraction (MAE) has several advantages over conventional extraction methods because its selective heating increases the effectiveness of the extraction process. The effect of different variables such as irradiation power, contact time and solid to solvent ratio was investigated. After extraction, regenerated spent bleaching earth (RSBE) is used in the bleaching of palm oil with activated bleaching earth (ABE) as a comparison. From this study it can be concluded that MAE can be used in the regeneration of SBE with hexane as solvent. The best conditions for each variable were an extraction time of 40 minutes, a solid to liquid ratio of 1: 4 and a microwave power of 450 W. Using RSBE, the highest yield obtained was 18.63%. Thus, RSBE can be reused in the bleaching process. However, to obtain the same quality results as treated using ABE, more RSBE is needed.
Ethnobotany of Medicinal Plants Community in Saroha Village, Tanjung Botung, Barumun District, Padang Lawas Regency, Uatara, North Sumatra
Authors: Rambey R , Lubis A S J
Published: January 2023

Indonesia is a country with a high level of diversity, both flora and fauna. One of the biological diversity that is owned is various types of medicinal plants used by the community. The purpose of this study was to make an inventory of the ethnobotany types of medicinal plants in the community around Saroha Tanjung Botung Village, Barumun District, Padang Lawas Regency. The research was conducted from July to November 2020 in Tanjung Botung Saroha Village, Barumun District, Padang Lawas Regency. The research method used is snowball sampling by means of interviews with key informants in the community. Based on the results of the study, there are 40 types belonging to 31 families of medicinal plants found in the village of Saroha Tanjung Botung as traditional medicine. The percentage of the most widely used family were Zingiberaceae (12,9%), Asteraceae (9,6 %), Malvaceae (6,45 %), Myrtaceae (6,45 %), Clusiaceae (6,45%) and Poaceae (6,45%).
Analysis of Eucalyptus Supply Chain Methods Based on Influencing Factors: A Review
Authors: Sembiring N , Napitupulu H L , Azmi N N , Radot R
Published: January 2023

The success of a supply chain is an important key in achieving the goals set by producers. The success of a supply chain has multiple objectives that are key to consumer satisfaction. These goals are high quality, low prices, on time delivery, and good customer service. This goal can be achieved if the management can design a good supply chain. In this study, an analysis will be carried out from the results of previous research, regarding the efforts made to increase supply chain productivity for Eucalyptus plants. Every scientific article goes through a rigorous selection process to get articles that are in accordance with the objectives of this research. The results show that the approach using simulation methods is the best way to analyze and evaluate a supply chain. Each simulation approach can provide actual information required for improvement of the supply chain. Improvements are generally carried out on an ongoing basis for each specified period.
Sustainable Development Goals and Green Sustainable Supply Chains: a Review
Authors: Sembiring N , Junika C , Azmi N N
Published: January 2023

This study establishes the practice of Green Supply Chain Management (GSCM) from a broad perspective and to analyze topics in recent years, by analyzing the literature review of articles published mostly in 2019-2020. The use of GSCM was developed by the concept of green innovation with new methods and ideas for producers. GSCM practices have an impact on environmental implementation that this study tries to find out how manufacturing organizations improve their environmental performance with green innovation practices and GSCM. This paper presents GSCM practices that provide practical evidence for organizations that contribute to determining their ideal environmental strategies. This study also contributes to innovations that enhance green innovation, and hence providers a broad assessment with consideration of green innovations at the green supply chain stage.
Computational Analysis for Dam Stability Against Water Flow Pressure
Authors: Tulus  , Marpaung T J , Marpaung J L
Published: January 2023

Fatigue analysis of an object’s structure is very important because it can provide a numerical value that can be used as a reference before acting. The finite element method is a numerical method that can calculate the value of the fatigue and stability of a structure by calculating the reynold value and the pressure given. This study aims to conduct a structural fatigue analysis of the dam that focuses on the Reynold value in order to provide an analysis and representation of the dam structure. The result to be achieved is a mathematical model that analyzes the fatigue of the dam structure by connecting the elevation angle, water velocity, time, and the force obtained from the kinetic energy in the water flow.
Finite element analysis of mechanical properties of bambusa vulgaris bamboo from eastern region of Sumatera Utara
Authors: Handana M A P , Surbakti B , Karolina R , Utami H
Published: January 2023

Indonesia is the right area to develop bamboo as a construction material because this country is a well-known bamboo producing country in the Asia-Pacific region. One of the bamboo species that can be studied is Bambusa vulgaris because this species grows in almost all parts of Indonesia. This study focused on Finite Element simulation to calculate the compressive strength and tensile strength of Bambusa vulgaris sourced from Deli Serdang, Langkat, and Sedang Bedagai district. The results of the strength obtained from the simulation will be compared with the results from the previous study with the same species and the same location, to see the reliability of the model simulation with software. From simulation results, it is found that the compressive strength is 46.70 MPa, 58.33 MPa, and 47.65 MPa. For tensile strength, the results obtained from the simulation are 194.08 MPa, 182.49 MPa, and 156.44 MPa.The difference given between the simulation result and the test results in previous studies for compressive strength is 5.38 – 10,09% and for tensile strength is 1,96 – 9,39%. This result indicates that simulation with Finite Element Analysis can provide results that are sufficiently close to a laboratory test.
Analysis of the relationship between urban heat island (UHI) phenomenon and land cover change in Medan city using Landsat satellite imagery
Authors: Pohan S A , Sulistiyono N
Published: January 2023

The increase in population accompanied by an increase in the amount of built-up land has led to an increase in the LST of many cities, including the city of Medan. The city of Medan is the capital of the province of North Sumatra, Indonesia. The utilization of Landsat satellite imagery can be used to monitor land cover changes and LST changes. This study aims to obtain information due to changes in land cover to LST in Medan City. The use of thermal Infrared band in Landsat satellite imagery can monitor LST changes that have occurred. The results of the study show that in the period 2000 to 2019 there has been an increase in the area of built-up land and a decrease in the area of vegetation in the city of Medan. In 2000 the LST ranged from 12-30°C while in 2019 it ranged from 18-33°C. This has triggered the occurrence of UHI, especially in urban centers in the city of Medan.
Design of Monitoring System Temperature And Humidity Using DHT22 Sensor and NRF24L01 Based on Arduino
Authors: Azhari  , Nasution T I , Sinaga S H , Sudiati
Published: January 2023

The monitoring system is used for know or get an information on a situation or condition in a certain place or area, with various methods used, so that many monitoring systems are developed and applied to assist human tasks in carrying out monitoring. The hardware design consists of 2 nodes namely the base node and the client node. At the base node there are 2 hardware components used, namely: Arduino Uno and the wireless communication module nRF24L01. The use of the NRF24L01 module is a reliable data communication module so that the data received is in accordance with the data sent by testing the module in different rooms and the same range with a distance of ± 800 m. Buzzer works well with temperature performance results ≥ 32 °C buzzer on and with ≤ 65% humidity buzzer on. The sensor network system can run well, because the ratio of the DHT22 sensor with the thermohygro, the average error is 1.4% for temperature and 3.8% for humidity from the results of data collection.
Simulation and design of the circular polarization microstrip antenna with CSRR metamaterial structure
Authors: Rambe A H , Nasution F A , Sinulingga E P
Published: January 2023

This paper has discussed the design of a circular polarized microstrip single patch antenna using a complementary split-ring resonator (CSRR) placed in the patch section. The design used an epoxy FR4 substrate with a thickness of 1.6 mm. Antenna specifications that resonate at a frequency of 1.57 GHz are very supportive for GPS applications. The design is carried out with the AWR simulator. The implementation of CSSR metamaterial structure in the patch was successful in improving the design performance compared to the design without using CSRR. Based on the simulation results, the minimum return loss is -40.92 dB at a frequency of 1.57 GHz and an axial ratio below 3 is achieved for the frequency range of 1.56 – 1.59 GHz. Reduction of substrate and patch dimensions was achieved by 36.5% and 46.9%, respectively.
Construction of Ultrasonic Fruit Fly Repellent Device in Orange Orchard
Authors: Rahayu S U , Nasruddin  , Susilawati  , Sianturi H A , Faturrahman  , Manurung J G
Published: January 2023

Ultrasonic waves are stated to be able to repel several types of pests. This study aimed to design a device to repel fruit fly in orange orchard using ultrasonic waves with a frequency range of 20-80 KHz. The device employed a microcontroller and real time clock (RTC) to control the ultrasonic wave transmitter automatically, in which the electrical energy is obtained from solar panel. The objective of using the solar panels is to directly powered device without installing the cable to the main power source (PLN) because the device should be placed in the middle of the orchard, which is located far from the main power source. Based on the design analysis, the solar panel should be placed facing the southern part of the orchard with the angle of around 5ºC since the orchard in the Karo regency, Sumatera Utara, Indonesia. The current was measured for each frequency, and based on that measurement the electrical power was calculated to be 142.56 Watt, so by using the battery of 1200 Watt, the device could work properly for 8 hours even without full sunlight. The resulted frequency was measured using oscillator; the results show that the average accuracy is 0.24%, which shows that the ultrasonic wave transmitters generate the ultrasonic wave accurately. Based on these results, it can be concluded that the ultrasonic fruit fly repellent device designed in this study is successfully constructed and works properly to generate the ultrasonic wave with the range frequency satisfied the condition to repel the fruit fly.
Humidity Detection Based on Chitosan/PEO Film Sensor
Authors: Cuana R , Nasution T I , Agusnar H , Susilowati A , Lubis N S , Pradana I S
Published: January 2023

PEO (Polyethylene Oxide) addition in chitosan has been successfully fabricated as a humidity sensor. In this study, 3% w/v chitosan solution was added by 0.1, 0.2, 0.3, 0.4 and 0.5 (%w/v) of PEO respectively. The sensing properties of chitosan and chitosan/PEO films as humidity sensors have been characterized using Air Handling Unit Trainer, model KT-2000AHU to determine response, repeatability, and recovery toward relative humidity (20-90% RH). The results show that the chitosan/PEO films have a good response when exposed to 90 %RH at room temperature. Those are 288,09 mV obtained by pure chitosan film; 338.97, 384.44, 406.81, 359.69, and 345.84 mV for 0.1, 0.2, 0.3, 0.4, and 0.5% of PEO films respectively that show higher electrical response. The smooth and porous film morphology and chemical interaction between chitosan and PEO through hydrogen bond obtained by SEM and FTIR could be responsible for the higher electrical response. Furthermore, humidity sensing material based on chitosan/PEO films shows good recovery and repeatability.
Effect of blanching treatment on drying time and the quality of hybrid system solar dried red chilli
Authors: Romauli N D M , Sihombing H V , Sinamo K N , Ambarita H , Manurung H
Published: January 2023

This research aims to determine the effect of blanching treatment and the effectiveness of hybrid system solar dryer for drying red chilli. The dried red chilli quality parameters such as moisture content, total microba and L*,a*,b* for colour values were determined. The experimental results showed the drying box of hybrid system solar drying can reach maximum temperature from 55.2°C to 57.1°C. Blanching treatment combined with hybrid system of solar drying shortened drying time, gave lower moisture content and lower total plate count of dried red chilli compared with nonblanched-conventional drying.
The approaches for the two parameters of the Weibull Distribution
Authors: Lestari S , Sutarman
Published: January 2023

This study aims to determine the MLE and Bayes approach on the Weibull distribution. Through literature study done by analyzing the MLE approach to the Weibull distribution and the priordistribution for Bayesian methods in this approach by using prior information Jeffrey expansion with two parameters α and β.
Computational analysis dynamics fluid of flow in dam using COMSOL Multiphysics
Authors: Masna  , Tulus  , Sawal
Published: January 2023

One way to utilize river flows in Indonesia is to make a dam to get benefits in various fields. The river flow that enters the dam and which will flow again makes flow in the dam which causes a fluid dynamics. The fluid dynamics that occur in dams produce several events such as precipitation, flow turbulence, and so on. To see how the flow is, in this study a simulation was carried out by making a dam model followed by fluid dynamics analysis of the dam model. Then it will be solved by the finite element method. In its completion, a COMSOL Multiphysics program is used that applies the finite element method to get results and simulations. The results to be obtained using the mesh transfer method. Where mesh displacement applies the speed of surface displacement as the velocity of fluid flow when entering, the solution to the equation in mesh displacement uses displacement on the node, and the Navier Stokes equation is solved by substituting the displacement equation on the mesh. The results obtained at an interval of approximately 3 seconds with a speed of 0.7 m/s will produce turbulence flow at the dam where the maximum speed on the surface is 0.4 m/s. As a result, if there are other elements in the flow other than water, it will cause mixing of substances in the middle of the dam in 3 seconds and then precipitation will occur. In the next study, different dam models will be carried out and have a faster flow rate.