bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorptive performance of green synthesized zinc oxide nanoparticles for the removal of cadmium (II) and lead (II) ions
Authors: Chukwuemeka-okorie H O , Ani J U , Agbo S C , Odewole O A , Ojo F K , Alum O L , Akpomie K G , Ofomatah A C , Aralu C C
Published: May 2023

This study has Zinc oxide (ZnO) nanoparticles (NPs) synthesized from the leaf extract of Costus Afers via a green approach. The synthesized zinc oxide nanoparticle (ZnO NPs) showed excellent adsorption capabilities towards Cd (II) and Pb (II) ions. ZnO NPs were characterized by Fourier Transform Infrared (FT-IR), Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD). The formation of ZnO NPs was confirmed by the absorption band at 825cm−1 and 747cm−1. The XRD and SEM analysis show the high purity and hexagonal structure of ZnO NPs with a crystallite size of 83.56 nm. A batch adsorption experiment was employed to examine the process parameters such as the effect of the initial pH of the solution, initial metal ion concentration, adsorbent mass, and contact time on the sequestration efficiency of Cd (II) and Pb (II) ions. The equilibrium isotherm models were studied using Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models. The Langmuir adsorption isotherm provided the best fit for the adsorption process with coefficient of determination (R2) values of 0.988 and 0.986 for cadmium and lead (II) ions respectively, indicating a monolayer surface on ZnONPs. The pseudo-second-order kinetics model presented a good fit for the adsorption of Cd (II) and Pb (II) ions on zinc oxide nanoparticles giving a correlation coefficient of 0.989 for Cd and 0.996 for Pb suggesting that chemisorptions are the rate-determining step.
Assessment of the Damage Incurred by biodiversity and ecological degradation via HEC-HMS simulations and of Stream Flow Assessment and Analysis (SAAS).A case study.
Authors: Agashua L O , Ogbiye A S , Oluyemi-Ayibiowu B D , Igibah E C , Ihimekpen I N , Wasiu J
Published: May 2023

Findings on the quality of River Ikpoba samplings is an essential matter because water resources management coupled with hydro-chemical interfaces is of the essence, especially for monitoring and discovering of surface-water contaminants origins. Thus, River Ikpoba samplings were scrutinized using Stream Flow Simulation Model (SFSM) and Multivariate Statistical techniques. Runoff occasion due to land use change shows increase in curve number at peak runoff of 11.60m3/s, while the maximum rainfall is greater in the circumstances up to 141.0 mm. All though the year, not only that envisaged medians always greater than the mean monthly scrutinized, but the anticipated minimum temperature is also bigger, i.e. even more unadventurous prognosis of temperature result in warmer climate scenario in the study region. As the computed runoff occasion p-value (0.998) is greater than the significance level alpha=0.05, one cannot reject the null hypothesis H0. Hence, it was concluded that the simulated flow data are closely related to the observed flow data. Likewise, an increase in curve number (from 74.58 to 79.99) resulted in a corresponding increase in outflow (from 8.00cms to 10.350cms) was observed. Indicating, with increasing curve number, the peak discharge and direct runoff volume also increases proportionately.
Assessment of Pollution Status of River Ajali in Enugu State Using water quality index
Authors: Alum Ogechi L. , Akpomie Kovo G. , Ofomatah Anthony C. , Chukwuemeka-Okorie Helen O. , Ani Julius U. , Agbo Sunday C. , Odewole Olufemi A. , Ojo Francis K. , Abugu Hillary O.
Published: May 2023

The physico-chemical and microbial examination of Ajali River in Ezeagu Local Government Area (LGA) of Enugu State, South-eastern Nigeria, were carried out to assess the characteristics of the water for potability. Water samples were collected from three sampling points, including the one close to the brewery effluent discharge into the river and two different points that were affected by non-point sources. Altogether, eighteen samples were collected for two years during the dry, early and late rainy seasons. The physico-chemical, as well as microbial analyses of the samples, were determined following the standard methods. Significant spatial and seasonal variations (p<0.05) were clear for some physico-chemical parameters such as pH, phosphate, and sodium. Mean values of the Water Quality Index (WQI) were: dry season (104.23±9.75); early rainy season (113.22±8.78) and the late rainy season (102.58 ± 11.15). All the values are above 100 showing that the calculated WQI in all the seasons is not good however after the addition of lime, boiling and filtering to increase the quality.
Investigation on the physicochemical properties of Nru clay deposit and its industrial application
Authors: Odewole Olufemi A. , Ojo Francis K. , Alum Ogechi L. , Akpomie Kovo G. , Ofomatah Anthony C. , Chukwuemeka-Okorie Helen O. , Ani Julius U. , Agbo Sunday C. , Omeje Emmanuel E.
Published: May 2023

The utility of Nru clay for industrial application, which was taken from the Nsukka local government area in Enugu State, Nigeria, is assessed in this study for its physical and chemical properties. The clay was investigated chemically which showed SiO
2 51.2%, Al
2
O
3 18.3% as the predominant constituents while other metallic oxides such as Fe
2
O
3 5.3%, MgO 2.2%, Na
2
O 1.8%, CaO 1.4%, K
2
O 1.3% and MnO 0.7% were present in considerable proportion. The physical and mechanical analysis acknowledged a range in the linear shrinkage (4.17 - 6.25%), total shrinkage (7.8 - 10.2%), apparent porosity (36.92 – 26.58%), apparent density (2.59 - 2.37 g/cm3), bulk density (1.63 - 1.74 g/cm3), water absorption (22.64 – 15.33%) and modulus of rupture (6.70 – 9.15 kg/cm2) with an increase in firing temperature from 900°C to 1200°C. Nru clay can withstand heat without melting or deforming at temperature up to 1200 °C and exhibited reasonable plasticity with a modulus of plasticity of 1.42. We can infer from our investigation that Nru clay is a potential raw material for industries in the production of ceramics, high melting clays, fired bricks, and paints. Alternatively, the clays’ properties can be tailored to achieve superior physical and mechanical properties by enhancing them with additives. Therefore, it can be employed to cushion the exorbitant cost of importing clay minerals from other nations.
Elevation angle effect on slant path attenuation along earth-space paths: A Northern Nigeria perspective
Authors: Tyokighir Soo , Mom Joseph , Igwue Gabriel
Published: May 2023

In the network planning and design of terrestrial and earth-space communication links, the slant path attenuation caused by rain and its associated strong winds is of interest. Rain causes severe link degradation to radio links by absorbing parts or the whole signal during propagation. This study predicts slant path attenuation by rain in three (3) Northern Nigerian zones using the International Telecommunications Unions (ITU-R) model for 10 to 40 GHz. The effect of specific attenuation, rain attenuation, and elevation angle on the received signal strength is analyzed. The ITU-R model suggests rain attenuation values ranging from 4.26 dB to 31.67 dB for Jaji, Wudil, and Potiskum. The results further indicate a decrease in rain attenuation with an increase in elevation angle up to 50.1° elevation for the three (3) monitored stations, which starts to decrease steadily after this threshold. Results from this study can aid the network engineer in anticipating network changes and planning fade mitigation techniques where necessary.
Comparing the impact of solar activities on rainfall under varying climates during the solar cycle 24
Authors: Obiegbuna C D , Orji O P , Enwelum C U
Published: May 2023

A ten-year (2009 – 2018) data sets of rainfall and sunspot numbers obtained from the Nigerian Meteorological (NIMET) agency and Sunspot Index and Long term Solar Observations (SILSO) respectively were studied using correlation and trend analysis and their results were compared. Variations in annual and monthly rainfall in Port Harcourt and Sokoto stations during solar cycle 24 were observed. The results of the correlation between rainfall (RF) and sunspot numbers (SSN) showed that all the months in Sokoto correlated negatively as expected while half of the months in Port Harcourt were negatively correlated. Again, monthly RF/SSN correlation results in Sokoto were high except in March, August, and December with -0.1827, -0.1338, and -0.0.1653 respectively, whereas only January, March, April, and May in Port Harcourt had high correlations with -0.5309, 0.5773, -0.5499, and -0.6710. While trend analysis of SSN and RF in Sokoto showed a coincidence in the peaks of Sunspot numbers and rainfall in 2014, that between SSN and RF in Port Harcourt showed that RF peaked 3 years after SSN peak. The results suggest a possible effect of solar activity on climate change and also the impact of aerosols and atmospheric air contaminations in the solar activity – rainfall relationship.
Effects of abattoir effluent and dumpsite on the physicochemical properties and heavy metal levels of soil and water within ogbor hill, Aba.
Authors: Ofomatah A C , Chukwuemeka-Okorie H O , Ani J U , Agbo S C , Odewole O A , Ojo F K , Alum O L , Akpomie K G , Ugwu K E
Published: May 2023

The physicochemical characteristics and heavy metal concentrations of the soil and water in Ogbor Hill, Aba were examined in relation to the effects of abattoir effluent and dumpsite. Samples were taken from the water in a borehole, an abattoir, and a dumpsite. These samples’ physicochemical characteristics and heavy metal concentrations were identified. The results showed that the borehole water had nickel and iron at concentrations of 0.15±0.07 mg/kg and 0.18±0.09 mg/kg, respectively, but no copper or lead. Iron levels in soil samples ranged from 4990.87±41.88 mg/kg to 5087.24±72.18 mg/kg, whereas those in wastewater samples ranged from 69.91±12.36 mg/kg to 569.57±38.64 mg/kg. The wastewater samples’ pH levels ranged from 6.35±0.21 to 6.5±0.00. The conductivity varied between 344±0.41 and 13538±0.83 uS/cm. Turbidity varied from 1.05±0.07 to 35.8±0.28 NTU, while the chloride ranged from 189.57±2.13 to 528.95±5.02 mg/L. The ranges for the biochemical and chemical oxygen demands were 20±1.13 mg/L to 120±1.13 mg/L and 65.6 ±2.26 mg/L to 319.6 ±0.57 mg/L, respectively. The soil’s pH ranged from 5.75±0.07 to 8.45±0.07, and its nitrogen level varied from 0.35±0.01 to 0.44±0.01 %. Sulfur levels ranged from 0.03±0.01 to 0.05±0.01 %. These results demonstrate that the abattoir and the dumpsite have not adversely affected borehole water, but the opposite is true of soil, according to WHO (2004) guidelines.
Sustainable energy and environmental management practices in the recreation and tourism industries in Nsukka metropolis of Enugu State
Authors: Abbah O I , Igwe N J , Ogwo U
Published: May 2023

Sustainable energy and good environmental management practices are potent factors that can be used to achieve clean energy and sustainable economic growth. This is a global problem that needs immediate action and intervention to reduce the adverse impact of climate change to humanity. This study investigated the sustainable energy and environmental management practices in the recreation and tourism industries in Nsukka metropolis of Enugu State. The descriptive research design was adopted for the study. The population of the study consisted of 209 recreation and tourism service providers in Nsukka Metropolis. Instrument for data collection was a structured questionnaire which was validated by three experts from the University of Nigeria, Nsukka. The instrument has a reliability coefficient of 0.81. Frequency and percentages were used to determine level of sustainable energy and environmental management practices, while phi coefficient was used to determine relationship between sustainable energy and environmental management practices. Findings showed that recreation and tourism possess very low level of knowledge of sustainable energy use. They however showed positive attitude towards sustainable energy through the adoption of energy saving devices like energy bulbs, solar PVs etc. There is strong positive relationship between knowledge of sustainable energy and environmental management practices. The researchers recommended that government should improve on its effort to create awareness of sustainable energy use and environmental management practices among the populace if the problem of climate change is to be abated.
Formulation of Palm Oil Based Fat Replacer and Its Application on Meat Analogue
Authors: Setyaningsih Dwi , Siregar Meilisa Syafrina , Pasaribu Pradinata Yopindo , Muna Neli
Published: May 2023

Fat replacer is food ingredients used to mimic and replace animal fat in food products. The demand of low saturated fat in food products increase because of health concerns related to degenerative disease. Vegetable oil in a liquid state must be solidified to mimic animal fat by the emulsification process. This study aims to create and formulate fat replacer using palm olein and palm stearin as a source of unsaturated fatty acid. The formula was composed with vegetable oil concentration of 30% (K1), 35% (K2), 40% (K3), 45% (K4), and 50% (K5). A concentration of 15% fat replacers emulsion was added to make a meat analogue. Proximate analysis from all treatments showed that meat analogue has water content in the range of 53.90–57.56%, ash content of 2.87–3.10%, protein content of 9.04–15.32%, fat content of 13.22–19.13% and carbohydrate content of 2.35–2.53%. Oil concentration in fat replacer affected to the texture and sensory properties of meat analogue. The results indicate that the five treatments comply with the national quality standards for meat sausages.
Biopolymer manufacturing from pectin extraction of jackfruit waste to increase oil production in EOR
Authors: Perdana Restu Hamdi , Afdhol Muhammad Khairul , Erfando Tomi , Setiawan Chandra , Saputra Ilham Dwi , Adam Fatrio
Published: May 2023

This research was conducted with the aim of making an alternative, nature-based biopolymer formed from the extraction of jackfruit peel pectin as a substitute for commercial polymers. The manufacture of this biopolymer is carried out by means of laboratory tests using conventional methods with a chemical extraction process on jackfruit skin. The raw material used is jackfruit skin (Artocarpus integer). Processing of jackfruit skin into pectin is carried out by several procedures such as extraction using citric acid, purification of pectin with 96% ethanol, FTIR characterization test, density test, viscosity test, shear rate test, and the effect of salinity. The FTIR test showed that pectin was formed after the extraction step, as evidenced by the structure of the pectin-forming groups which was similar to commercial pectin. The deposition of impurity particles contained in the pectin content is evidenced by the lack of optimal pectin to increase the viscosity of water. The increase in viscosity will occur as the concentration of pectin increases. Jackfruit pectin is able to survive in solutions that have high salinity, as evidenced by the higher the salinity of the solution, the thickening process continues.
Microalgae Photobioreactor for Carbon Dioxide Fixation and Production of Biofuel Feedstock
Authors: Admirasari Rahmania , Rifai Agus , Prayitno Joko , Santoso Arif Dwi , Susanto Joko Prayitno
Published: May 2023

Microalgae cultivation is considered fit to the concept of green economy, in which greenhouse gases (GHG’s) mitigation and production of valuable substances is performed simultaneously. Carbon dioxide consumption by the algal cells reduces GHG’s emission to the atmosphere, while biomass conversion to biofuel feedstock supports the concept of circular economy of microalgae cultivation process. In this study, Chlorella sp. was cultivated in a Multi Tubular Airlift Photobioreactor (MTAP) system with a total volume of about 600 L. The result of a thirteen days batch culture showed the ability of the system to fix 1.57 g CO2 L-1 day-1. At the last day of experiment, 600 L MTAP showed biomass production of 0.35 g L-1 and 18% oil from cell dry weight was observed. This research showed the ability of 600 L MTAP to absorb 942 g CO2 and produce 37.8 g oil as biofuel feedstock. Compared to other experiments, percentage of oil in this experiment (18% from cell dry weight) was in the average range from other experiments (of about 10 – 40% from cell dry weight). However, this MTAP showed higher performance than other systems (mostly below 1 g CO2 L-1 day-1) in CO2 fixation rate.
Physical and Mechanical Properties of Starch Foam Reinforced with Pineapple (Ananas comosus) Leaves Powder
Authors: Nugroho Agung , Legowo Agung Cahyo , Maharani Dessy Maulidya , Khairunnisa  , Ghofur Abdul
Published: May 2023

Investigation of capability of high potential pineapple (Ananas comosus) leaves powder (PLP) as reinforcing material on the starch-based foam production has not been reported. This study was aimed to characterize the physical and mechanical properties of starch foam formed from the mixture of cassava starch and PLP. The foams were made using a baking process on a thermo-pressing machine at temperature of 170°C and 180°C of the lower and upper mold temperature during 120 seconds. The starch foams were formulated with four different concentrations (0, 5, 10, and 15%) of PLP as reinforcement and tested for their characteristics of mechanical (compressibility) strength, water adsorption, morphological structure, density, color appearance, and biodegradability. Addition of PLP up to 15% improved the physical and mechanical properties of the foams.
Investigation of Biodiesel Stability under Vacuum Heating Process
Authors: Pamungkas Ade , Solikhah Maharani Dewi , Pratiwi Fatimah Tresna , Romelan  , Matheofani  , Wirawan Soni Solistia
Published: May 2023

High water content is one of the most concerning issues when implementing biodiesel as a diesel fuel blend. Vacuum heating is one of several methods to reduce the water content of biodiesel, at certain conditions, it may damage the stability of biodiesel. This study aims to understand the stability of biodiesel including water content, total acid number, and oxidation stability under vacuum heating process. The three stability parameters were tested according to ASTM D6304, ASTM D664, and EN 15751, respectively. Biodiesel with high water content was heated under a vacuum pressure of -720 mmHg. The heating temperature and time were varied to determine the effect of both variables on the stability of biodiesel. The result shows that higher heating temperature produces lower water content and higher reduction of oxidation stability. Similar effects were also observed at a longer heating time. However, either temperature or time variations gave no noticeable effect on the acid number, while oxidation stability can be maintained above 22 hours. The results of this study can be used as a recommendation in determining the limits of acceptable operating conditions in the biodiesel vacuum heating process.
Evaluation of Quality of Biodiesel and Diesel Fuel with High Ratio Blends
Authors: Hidayat J A , Sugiarto Bambang , Anggarani Riesta , Aisyah Lies , Fathurrahman Nur Allif , Yogi P , Muhammad Riza F , Muhammad Hasfi N , Umar
Published: May 2023

The limited availability of fossil fuels and the current issue of global warming has made biodiesel an alternative The first section in your paper fuel option. Biodiesel, which is processed through the transesterification reaction in its use has been approved as a commercial fuel with a low blending ratio. However, it is possible to use it with a high ratio. Blending biodiesel and diesel fuel with a high ratio, of course, many considerations must be agreed upon regarding the quality of the product. In this study, the quality of the biodiesel-diesel blending was evaluated. Characterization of the blending fuel properties with improvement was carried out to evaluate the characteristics of the fuel blending and to indicate the maximum blending ratio that is suitable for use and does not harm the environment or its users. Diesel fuel (B0) with a cetane number of 48 and a cetane number of 51 is blended with FAME (B100) from a ratio of 10% FAME and 90% diesel (B10) to 90% biodiesel and 10% diesel (B90). Characteristics such as viscosity, density, FBT, Cleanliness, total contaminants, and CFPP were tested according to ASTM and ISO standards. The results showed an increase in the value of viscosity and density as the ratio increased but still met the ASTM D7467 standard of 0.855 mg/m3 in the B90 and the highest viscosity was 4.9 mm2/sec in the B70. The results of the FBT test, total contaminant, cleanliness, and CFPP the highest on B90 for all fuels.
Utilization of Rice Straw Extract as Corrosion Inhibitor to Decreasing Effect of Elevation on CS Pipeline using Olga Simulator
Authors: Pramana A A , Afif M I
Published: May 2023

In many infrastructure of oil and gas industries, corrosion is one of the most problems that often occur, especially in pipelines. Corrosion is caused by an electrochemical reaction between material surface and corrosion fluid. This problem will affect the economy, safety, and conservation. In this case, we should give a solution such as a method or tools to minimize corrosion’s effect so, it can improve safety and minimize the potential problems caused by corrosion and loss more cost. One of the ways is using organic corrosion inhibitors such as biomass agriculture waste and plant extract. A corrosion prediction model can be used to predict the corrosion rate such as NORSOK and de Waard models. Both methods are available in Olga Simulation software by Schlumberger that were used in this paper. Some of the parameters that influence corrosion were also tested: Evaluation of 1°, 2°, 3°, 4 °, and 5° of pipeline elevation to corrosion rate. Meanwhile, 31.71% of rice straw extraction (RSE) with 75% IE was used as a corrosion inhibitor compared with 30% of mono-ethylene glycol with 26% IE and 38.97% of lignin with 61% IE to determine the period of pipeline per year and to design of the pipeline. RSE that contains lignocellulose was able to give higher efficiency to decreasing corrosion. Moreover, this organic inhibitor give low cost. Therefore, this biomass would be potential as an alternative inhibitor rather than a commercial corrosion inhibitor with high cost.
Determination of Chemical Content of Porang Flour (Amorphophallus muelleri blume) by Near Infrared Spectroscopy
Authors: Budiastra I W , Noviyanti A A
Published: May 2023

Porang is well known with its high glucomannan content. Determination of the chemical content of porang flour is commonly carried out by chemical methods in the laboratory, which are known to take a long time and expensive. This study aims to determine the chemical content of porang flour using near infrared spectroscopy (NIRS). The reflectance of porang flour was measured using an FT NIR spectrometer at a wavelength of 1000 to 2500 nm. The chemical content (water and glucomannan content) of porang flour was determined by oven and spectrophotometry as the reference method. The reflectance was transformed to absorbance and several spectral pre-treatments such as normalisation, detrending, standard normal variate (SNV), orthogonal signal correction (OSC), and multiplicative scatter correction (MSC) with various PLS and PCR factors number were applied to obtain the best chemical content prediction of porang flour with NIRS. PLS and PCR were used for calibration of NIR spectra and chemical content of porang flour. The best calibration for determining the moisture content of porang flour was obtained using NIR spectra with normalisation pre-treatment and 8 PLS factor (r=0.92; SEC=0.15%; CV=2.13%; RPD=2.68). The best calibration for determining the glucomannan content of porang flour was NIR spectra with detrending pre-treatment at PLS factor 7 (r=0.86; SEC=0.54%; CV=0.90%; RPD=1.62). A lower accuracy was obtained for predicting water and glucomannan content using PCR calibration method. For water content, the best calibration was obtained by NIR spectra with normalisation pre-treatment and 12 PCR factors (r=0.91; SEC=0.16%; CV=2.21%; RPD=2.59). For glucomannan content, the best calibration was NIR spectra using detrending pre-treatment at 9 PCR factors (r=0.81; SEC=0.62%; CV=0.94%; RPD=1.55). This study shows that NIRS can be used to determine the chemical content of porang flour.
Dynamic LCA of fuel cell-assisted bike in consideration of Pt catalyst degradation in various operating conditions
Authors: Nagado Ryuta , Sakai Satoshi , Ezawa Tomoya , Shimogawa Junnosuke , Katayama Noboru , Miao Shan , Dowaki Kiyoshi
Published: May 2023

Fuel cell (FC) systems have recently become increasingly popular in large applications, such as FC vehicles and stationary FC power systems for residences. The use of FC systems in smaller applications, such as electrically power-assisted bicycles and drones, is expected to expand. FC systems exert a low environmental impact during operation. However, in the future, the environmental impact during the manufacturing phase ought to be additionally considered. There is a concern that the sale of products may be restricted, if they fail to meet legal standards, such as the life cycle assessment (LCA) regulations in the EU countries. For instance, in TC 105 of the International Electrotechnical Commission (IEC), the technical specification of LCA methodology for a stationary FC co-generation system was issued. This study evaluates the abiotic depletion potential (ADP) in the manufacturing phase and global warming potential (GWP). As the platinum (Pt) catalyst of FC significantly impacts the environment, more than lithium and cobalt, used in conventional lithium-ion batteries, each FC application ought to be designed considering all life cycle stages, while optimizing performance product life. As a promising example, we analyzed the performance drop caused by Pt degradation during the use phase of the assisted bicycle. Moreover, the dynamic performance of the FC-assisted bikes with an FC device and the supplemental power source of a Li-ion battery were evaluated under various operating conditions.
Dynamic LCA of H2S adsorption from bio-syngas using mine residues
Authors: Torii Kento , Kumon Shoichi , Sato Kimitaka , Kato Shogo , Dowaki Kiyoshi
Published: May 2023

Hydrogen production from biomass and fuel cells is effective with respect to its small eco-burden and high energy efficiency. However, it is established that hydrogen sulfide (H2S) in gasified biomass (bio-syngas) can reduce the efficiency of fuel cells. To maintain high efficiency, H2S is removed by impurity adsorption. Although metal oxides are generally used as adsorbents, these can adsorb H2S only a single time, and the large amounts used represent an eco-burden. To overcome this problem, the use of mine waste (neutralized sediment) containing highly reactive iron was examined in a previous study, with H2S as an adsorbent to maintain a small eco-burden. It was found that its eco-burden is smaller than that of using metal oxides at 300°C. However, the authors treated the inlet H2S concentration, which affects sulfur capture capacity, as a constant, whereas the H2S concentration of biogas typically fluctuates dynamically between 50 and 1,200 ppmv. In addition, it is necessary to consider real situations from the perspective of a dynamic life cycle assessment. Consequently, it is necessary to determine the amounts of adsorbent used by considering changes in inlet H2S concentration. In this study, we investigated the relationship between changes in the inlet H2S concentration and sulfur capture capacity of neutralized sediment. The amounts used and eco-burden of neutralized sediment were calculated based on our experimental results, and on the basis of our findings, we established that the global warming potential of the proposed system at 300°0 was 70.7% smaller than that obtained using a metal oxide.
Financial Feasibility Analysis of Product Modification Cinnamon Java Roll as an Alternative to Sweet Snacks for People with Diabetes mellitus
Authors: Nurdialy Mela , Hangesti Emi Widyasari R.A. , Devy  , Widodo Gatot
Published: May 2023

The cinnamon plant that grows a lot in Indonesia provides bioactive components with health benefits, especially as a functional food used to avoid diabetes mellitus. There is an alternative snack for people with diabetes mellitus is cinnamon rolls. The study showed the following results: the production’s Break-Even Point (BEP) of 8,715 pieces, BEP of sales of IDR 139,446,148, Return on Sales of 43.96%, Return on Investment (ROI) of 462%, the NPV of IDR 624,120,256.97. Discounted Payback Period (DPBP) of 0.24-year, Profitability Index of 12.53, and Accounting Rates of Returns (ARR) of 98.9%. In conclusion, Cinnamon Java Roll is feasible for business, providing minimum product sales of 50.7%.
The Effect of Variations in Methanol Concentration on the Esterification Process against Quality of Biodiesel from Used Cooking Oil
Authors: Dewi Mubarokah Nuriaini , Maulana Safana Tsabita Nurani , Nurani Maulana Safira Tsafiqa , Sesira Michelle Sarah , Husein Alamsyah Muhammad Iqbal , Sandi Samuel Armawan
Published: May 2023

Used cooking oil has the potential to be used as raw material for biodiesel. However, the high Free Fatty Acid (FFA) content in used cooking oil can interfere with the transesterification process. This issue will affect the quality of biodiesel yields. Therefore, FFA content in used cooking oil must be reduced through a pre-treatment process by adding activated carbon adsorbent from charcoal. In this study, the adsorption process was carried out by mixing used cooking oil and activated carbon using 20% NaOH for 3 hours. Then the degumming process was carried out by adding 0.5% v/v HCl from the volume of used cooking oil. Then add 0.5% NaOH by weight of used cooking oil and distilled water gradually, accompanied by heating to a temperature of 120 °C. In the esterification stage, the variables used are the comparison of methanol with a ratio of 1: 2, 1: 4, 1: 6, 1: 8, and 1:10. In this study, the lower acid number obtained from all variables was 2,24 mg KOH/g sample. Meanwhile, the most optimal result was the 1: 2 variables with a density of 0.8531 g/ml, and the kinematic viscosity at 40°C was 4.94 mm2/s.
Glycerol and monoglycerides determination in biodiesel methyl ester from palm oil using gas chromatography
Authors: Katili Marsha , Bethari Sylvia Ayu , Sujarwati Widi , Devitasari Rossy Dwi , Anggarani Riesta , Aisyah Lies , Wibowo Cahyo Setyo , Fathurrahman Nur Allif
Published: May 2023

Monoglycerides and glycerol are by-products contaminants, after transesterification, in biodiesel that can lead to severe operational and engine problems such as wax precipitation, filter plugging and engine deposits. Therefore, strict regulations have been made, and accurate quality control is required. In this work, levels of monoglycerides and glycerol were determined using gas chromatography (GC) equipment with flame ionization detector (FID) refers to standard methods ASTM D6584 and EN 14105. However, the monoglycerides determination still needs firmness and validation to develop standard calibration series to fit the constituent fatty acid components of the feedstock used. This paper shows three fatty acids, i.e., monoolein, monopalmitin, and monostearin, as major components in palm-based biodiesel, which would be prepared as standard calibration and determined from commercial biodiesel samples in the determination of monoglyceride levels accurately and thoroughly. The result shows that standard solutions produce a curve with high linearity; it was above 0.998 (for free glycerol, monopalmitin, monoolein, and monostearin) and its accuracy values were >95%. However, the result for eight commercial biodiesel samples in Indonesia had a range of 0.23-0.54% w/w for total monoglycerides, 0.07 to 0.14 (% w/w) for total glycerol, and < 0.01% w/w for free glycerol, which was fulfilling to the ASTM D6751 and EN 14214 specification requirements.
Assessing water affinity properties of biodiesel, diesel fuel, and blends by measuring water saturation and water absorption
Authors: Abdurrojaq Nurmajid , Nulhakim Lukman , Zaelani Rizal , Ginanjar Kemal , Anggarani Riesta , Aisyah Lies , Fathurrahman Nur Allif , Wibowo Cahyo Setyo
Published: May 2023

Biodiesel has many advantages and technical aspects of being blended in any proportion with diesel fuel to support diversification energy policy. However, biodiesel absorbs more moisture than diesel fuel since methyl esters are hygroscopic compounds, and there is a limited amount of published information about water affinity properties. Water content can affect the fuel’s characteristics, reducing fuel quality if it accumulates into free, emulsion, or soluble water. This paper reports the water affinity properties of biodiesel, diesel fuel, and their blends through water saturation. It indicates a maximum water content value that the fuel can retain at a specific temperature and moisture absorption by controlled temperature and humidity. The results show that the pristine biodiesel has a water saturation range of (1366 to 1771) mg.kg-1 in the temperature range of (288.15 to 313.15) K. Therefore, diesel fuel has a maximum water saturation of 255 mg.kg-1 at a temperature of 313.15 K. The water saturation curve shows that biodiesel-diesel blends have a water saturation with a slope range of (12.20 to 15.11) mg.kg-1 water per 1%-vol biodiesel in diesel fuel blend in the temperature range (288.15 to 303.15) K. During eight days of observation on eight commercial biodiesels, the moisture absorption value was 1094 mg.kg-1 at a temperature of 298.15 K with a relative humidity of 90 %. It was also found that high moisture quickly affects the water content point in the storage period.
Process simulation and distillation unit design vacuum fractionation of rhodinol from citronella oil
Authors: Ayunda OR , Rusli MS , Agustian E
Published: May 2023

The application of biodiesel will increase in accordance with the government’s mandatory program for saving fossil fuels. The challenging would come from particulate levels and water content. One of the efforts to fix the issues is by adding rhodinol from citronella oil as an additive. This research was conducted to design a vacuum distillation process which has 500L of capacity and determine the design of the fractionation distillation unit. Simulation was carried out using the Aspen HYSYS software. The result of the simulation is expected to provide an overview of the fractionation process that would comply with the standard after some data validation. The simulation was applied by vacuum pressure in 4-5 mbar and variation of reflux ratios 1,2, and 3. The best simulation obtained was reflux ratio 2 at 47.80% geraniol and 61.34% citronellol concentrations. The simulation also obtained the following results are maximum and minimum pipe diameter of 0.04 m 0.02 m, the maximum and minimum thickness of 3.7 mm 2.8 m, column height of 10.5 m, column diameter of 0.2412 m, and thickness of 3 mm, condenser length and diameter of 1.11 m and 0.2032 m, reboiler length, and diameter of 1.5 m and 0.6515 m.
Synthesis of Ketones from Palm Fatty Acids Over Layered Double Hydroxide Mg/Al/Cu Catalyst
Authors: Soejana Firman Arief , Hambali Erliza , Farobie Obie
Published: May 2023

The synthesis of ketones from C18:1 fatty acid using the fatty acid decarboxylation method has been carried out to increase the added value of oil palm derivative products. One of the derivative products of palm oil is Crude Palm Oil, which can be converted into fatty acids through the triglyceride hydrolysis process. Currently, palm oil fatty acids are the most potential environmentally friendly raw material in Indonesia. This research aims to synthesize ketones from palm oil fatty acids under different fatty acid types and catalyst concentrations. Ketone compounds were synthesized using a base catalyst of solid layered double hydroxide based on Mg/Al/Cu environmentally friendly because it does not produce by-products that can become pollutants. The ketone product was analyzed using the Fehling test, Tollens test, and FTIR. The results showed that the success of ketone synthesis using the fatty acid decarboxylation method into ketones through the Fehling test that red brick precipitate did not form and the Tollens test also indicated no silver mirror formation. Meanwhile, the results of the FTIR test showed the presence of ketone compounds at peak frequencies of 1697–1710 cm-1. This study confirms that ketones produced from fatty acids have the potential to be environmentally friendly raw materials for diesel fuel, lubricants, and surfactants.
Simultaneous bioconversion of rice straw into an intermediate product using ionic liquid and native extracellular hydrolytic enzyme from indigenous actinomycetes
Authors: Satria H , Yuwono S D , Rinawati  , Nurhasanah  , Ellen AY
Published: May 2023

Bioethanol production technology using lignocellulosic substrates has become a focus to overcome the limited supply of fossil fuels in the current century. Simultaneous saccharification requires an understanding of suitable efficient procedures in bioconversion row material into fermented sugar. In this study, the effect of pre-treated rice straws using ionic liquid on enzymatic saccharification by isolated actinomycetes was investigated. Ionic liquid to rice straw in a ratio (IL/RS) was set up 0 to 3 (g/g), and the remaining of the ionic liquids in pre-treated biomass was examined for their effect on the hydrolytic enzyme activity of the actinomycetes. Three actinomycetes were isolated from decomposed rice straw and were purified and screened for their cellulolytic and xylanolytic activity; one strain, namely ActRS-4, was selected as an optimum isolate for further hydrolysis examination. Both cellulase and xylanase activity exhibit a peak at a ratio IL/RS of 1 (g/g), the activity was 27.72 and 66.16 U/ml, respectively. The highest yield of sugar was also achieved at this IL/RS ratio for 8 days of incubation. The pretreatment indicates that it could promote an increase in the yield of glucose and xylose by 28% and 37% respectively. This study was promising to develop a one-pot conversion of lignocellulosic biomass into bioethanol using the biological process.
Minor extensions of the logistic equation for growth curves of word counts on online media: parametric observation of diversity of growth in society
Authors: Watanabe Hayafumi
Published: May 2023

To understand the growth phenomena in collective human systems, we analyzed monthly word count time series of new vocabularies extracted from approximately 1 billion Japanese blog articles from 2007 to 2019. In particular, we first introduced the extended logistic equation by adding one parameter to the original equation and showed that the model can consistently reproduce various patterns of actual growth curves, such as the logistic function, linear growth, and finite-time divergence. Second, by analyzing the model parameters, we found that the typical growth pattern is not only a logistic function, which often appears in various complex systems, but also a non-trivial growth curve that starts with an exponential function and asymptotically approaches a power function without a steady state. We also observed a connection between the functional form of growth and the peak-out behavior. Finally, we showed that the proposed model and statistical properties are also valid for Google Trends data (English, French, Spanish, and Japanese), which is a time series of the nationwide popularity of search queries.
A structure theory for stable codimension 1 integral varifolds with applications to area minimising hypersurfaces mod 𝑝
Authors: Minter Paul , Wickramasekera Neshan
Published: May 2023

For any

Q
∈
{

3
2

,
2
,

5
2

,
3
,
…
}

Q\in \{\frac {3}{2},2,\frac {5}{2},3,\dotsc \}

, we establish a structure theory for the class

S

Q

\mathcal {S}_Q

of stable codimension 1 stationary integral varifolds admitting no classical singularities of density

>
Q

>Q

. This theory comprises three main theorems which describe the nature of a varifold

V
∈

S

Q

V\in \mathcal {S}_Q

when: (i)

V
V

is close to a flat disk of multiplicity

Q
Q

(for integer

Q
Q

); (ii)

V
V

is close to a flat disk of integer multiplicity

>
Q

>Q

; and (iii)

V
V

is close to a stationary cone with vertex density

Q
Q

and supports the union of 3 or more half-hyperplanes meeting along a common axis. The main new result concerns (i) and gives in particular a description of

V
∈

S

Q

V\in \mathcal {S}_Q

near branch points of density

Q
Q

. Results concerning (ii) and (iii) directly follow from parts of previous work of the second author [Ann. of Math. (2) 179 (2014), pp. 843–1007].

These three theorems, taken with

Q
=
p

/

2

Q=p/2

, are readily applicable to codimension 1 rectifiable area minimising currents mod

p
p

for any integer

p
≥
2

p\geq 2

, establishing local structure properties of such a current

T
T

as consequences of little, readily checked, information. Specifically, applying case (i) it follows that, for even

p
p

, if

T
T

has one tangent cone at an interior point

y
y

equal to an (oriented) hyperplane

P
P

of multiplicity

p

/

2

p/2

, then

P
P

is the unique tangent cone at

y
y

, and

T
T

near

y
y

is given by the graph of a

p
2

\frac {p}{2}

-valued function with

C

1
,
α

C^{1,\alpha }

regularity in a certain generalised sense. This settles a basic remaining open question in the study of the local structure of such currents near points with planar tangent cones, extending the cases

p
=
2

p=2

and

p
=
4

p=4

of the result which have been known since the 1970’s from the De Giorgi–Allard regularity theory [Ann. of Math. (2) 95 (1972), pp. 417–491] [Frontiere orientate di misura minima, Editrice Tecnico Scientifica, Pisa, 1961] and the structure theory of White [Invent. Math. 53 (1979), pp. 45–58] respectively. If

P
P

has multiplicity

>
p

/

2

> p/2

(for

p
p

even or odd), it follows from case (ii) that

T
T

is smoothly embedded near

y
y

, recovering a second well-known theorem of White [Proc. Sympos. Pure Math., Amer. Math. Soc., Providence, RI, 1986, pp. 413–427]. Finally, the main structure results obtained recently by De Lellis–Hirsch–Marchese–Spolaor–Stuvard [arXiv:2105.08135, 2021] for such currents

T
T

all follow from case (iii).
Polynomial approximation of symmetric functions
Authors: Bachmayr Markus , Dusson Geneviève , Ortner Christoph , Thomas Jack
Published: May 2023

We study the polynomial approximation of symmetric multivariate functions and of multi-set functions. Specifically, we consider

f
(

x
1

,
…
,

x
N

)

f(x_1, \dots , x_N)

, where

x
i

∈

R

d

x_i \in \mathbb {R}^d

, and

f
f

is invariant under permutations of its

N
N

arguments. We demonstrate how these symmetries can be exploited to improve the cost versus error ratio in a polynomial approximation of the function

f
f

, and in particular study the dependence of that ratio on

d
,
N

d, N

and the polynomial degree. These results are then used to construct approximations and prove approximation rates for functions defined on multi-sets where

N
N

becomes a parameter of the input.
Clinically Occult Diffuse Pleural Mesothelioma in Patients Presenting With Spontaneous Pneumothorax
Authors: Fels Elliott Daffolyn Rachael , Konopka Kristine E , Hrycaj Steven M , Lagisetty Kiran H , Myers Jeffrey L , Farver Carol F , Huang Tao
Published: May 2023

Objectives

To report histologic features of unsuspected diffuse pleural mesothelioma (DPM) in surgical specimens for pneumothorax and demonstrate how ancillary markers support a diagnosis of malignancy in this context. We explored whether pneumothorax may be a clinical manifestation of mesothelioma in situ (MIS).

Methods

A single-institution database search identified patients who underwent surgical resection for spontaneous pneumothorax (n = 229) and/or were diagnosed with DPM (n = 88) from 2000 to 2020.

Results

Spontaneous pneumothorax without clinical, radiologic, or intraoperative suspicion of mesothelioma was the initial presentation in 2 (2.3%) of 88 patients diagnosed with DPM. This represented 0.9% (2/229) of all patients undergoing surgical management of pneumothorax but accounted for a larger proportion of older patients (12.5% older than 70 years). Immunohistochemistry for BAP-1 and/or MTAP confirmed the diagnosis of DPM in 2 cases. Mesothelioma in situ was identified retrospectively by immunohistochemistry in 1 case of spontaneous pneumothorax from a 77-year-old man who developed invasive DPM 25 months later. No additional cases of MIS were identified in 19 surgical lung resections for spontaneous pneumothorax.

Conclusions

Histologic examination of bleb resections with ancillary testing for cases with ambiguous features is essential for detection of early DPM. It is uncertain whether spontaneous pneumothorax may represent a clinical manifestation of MIS.
Evaluation of a novel blood volume–based enoxaparin dosing guideline for venous thromboembolism prophylaxis in trauma patients
Authors: Langenstroer Elizabeth A , Carver Thomas W , Herrmann David J , O’Keefe Mary M , Hubbard Sara , Holschbach Leah , Rein Lisa , Peppard William J
Published: May 2023

Purpose

Fixed-dose and body mass index (BMI)–based enoxaparin regimens provide inadequate venous thromboembolism (VTE) prophylaxis for many trauma patients. The purpose of this study was to evaluate the effectiveness of a novel blood volume (BV)–based enoxaparin guideline vs a historical BMI-based guideline for VTE prophylaxis in trauma patients.

Methods

This was a retrospective pre/post study completed at a large academic level 1 trauma center. All adult trauma patients admitted from October through December 2019 and August through October 2020 who received prophylactic enoxaparin per guideline were included. The BV dosing was as follows: patients with a BV of 3 to 4.9 L received enoxaparin 30 mg every 12 hours, those with a BV of 5 to 6.9 L received 40 mg every 12 hours, and those with a BV of ≥7 L received 60 mg every 12 hours. The primary outcome was the percentage of patients who attained a target anti–factor Xa (anti-Xa) postdosing level at the first steady-state assessment (0.2 to 0.5 IU/mL).

Results

A total of 241 patients (99 for the BMI group and 142 for the BV group) were included. The study groups had a median age of 38 vs 42 years, a mean BMI of 27.4 vs 27.7 kg/m2, and a mean BV of 5.1 vs 5.1 L, respectively. A total of 63 patients (62.6%) in the BMI group attained target anti-Xa levels compared to 115 patients (81%) in the BV group (P = 0.008). In multivariate regression, the BV-based guideline was the only variable associated with attainment of target anti-Xa levels (adjusted odds ratio, 2.02; P = 0.01). Clinically relevant bleeding and VTE rates were similar between the groups.

Conclusion

Dosing prophylactic enoxaparin using a BV-based dosing guideline significantly increased attainment of target anti-Xa levels.