Initial Product Research Articles

Reservoir Drilling and Openhole Gravel Packing with High-Density Cesium Formate Fluids in a High-Pressure, Marginal Mud Window Environment at Martin Linge

Summary High-density cesium/potassium (Cs/K) formate fluids were successfully utilized from reservoir drilling to upper completion installation in five productive Martin Linge high-rate gas wells. Four wells were completed with openhole gravel pack (OHGP) and one with standalone sand screens. The gravel packing operation marks what is considered to be the highest density carrier fluid OHGP successfully completed worldwide, with a specific gravity (SG) of 2.06. A complex operation under pressure and temperature conditions (745–780 bar and 135–140°C) that almost qualify as high pressure/high temperature (HP/HT), including managed pressure drilling (MPD), overbalanced screen running, and openhole gravel packing, was simplified by using the same base brine throughout the operation. Cs/K formate reservoir drilling fluid (RDF) and screen-running fluid were designed with biopolymeric additives and minimal calcium carbonate bridging particles. Clear Cs/K formate brine was chosen as gravel pack (GP) carrier fluid. The use of Cs/K formate fluids for all stages of the operation reduced the complexity of transitioning between the operational stages. In addition, the reservoir was only exposed to one filtrate without application of damaging weighting solids. The drilling fluid contributed to successful MPD and delivered wells with very good hole quality in the reservoir, which consisted of interbedded sandstone, coal stringers, and shale. The shale-stabilizing properties of concentrated formate brine–based fluids provided acceptable conditions for extended openhole time and allowed additional logging runs, including pore pressure measurements, under near-HP/HT conditions, before running the screens. One bottom-up cleanout was conducted before the screen-running fluid was circulated in and the screens installed. The spurt and seepage losses were low throughout the drilling and screen-running phases. No breaker treatment was required in any of the wells. All wells have proved to have good initial productivity and high well productivity index. The successful OHGP operations performed with the high fluid densities required in Equinor’s Martin Linge field have set a new standard for well completions in challenging high-pressure environments.

Degradation of oil and oil products by microorganisms isolated from the Azerbaijani coast of the Caspian Sea at low temperatures

The object of the study is microorganisms isolated from the Azerbaijani territory of the Caspian Sea, capable of decomposing oil and oil products at low temperatures of 4–6 °C. The purpose of this work was to study bacteria and fungi capable of actively assimilating oil, gasoline, kerosene, diesel fuel at a temperature of 4–6 °C in order to solve the problem of environmental pollution in this region. The studied most effective biodestructors are combined into associations that can be used to create an active biological product based on native microorganisms with its further use for water bioremediation, as well as treatment of tanks and other containers used for long-term storage of petroleum products at a temperature of 4–6 °C. The process of degradation of samples of used oils at the molecular level of the selected compounds was studied by reverse-phase high-performance liquid chromatography. As a result of chromatographic and spectroscopic studies, it was found that almost all microorganisms decompose the tested oil products. Only weak peaks remained on the chromatogram, which is a clear indicator of the deep biodegradation carried out by these microorganisms. Thanks to the chromatographic and spectral analysis of oil and products of its decomposition, an oxidation sequence has been established, indicating the decomposition of the last aromatic fraction. As a result, a general picture was obtained on the amount of degradation products containing carboxyl, keto-, hydroxyl groups, which is not enough to determine the processes of transformation of initial products into final ones. All this testifies to the multidirectionality of biodegradation processes

Development of symbolic modeling videos containing syair gulung to improve students' social citizenship harmony

Based on needs assessments in the field, Guidance and Counseling Teachers need guidebooks and symbolic modeling videos containing interesting and fun local wisdom. Guidebooks and symbolic modeling videos containing Syair Gulung are designed to improve students' social and civic harmony. The composition of rolled poetry lines and symbolic modeling videos can have an effect on changes in students' cognitive and behavior. The aim of this research focuses on producing products, namely guidebooks and Syair Gulung videos. Research and development is hereby adopted from Borg and Gall, then modified according to needs and limitations in the field using seven steps, namely (1) preliminary study; (2) carry out planning; (3) initial product development; (4) initial product validation by assessors; (5) product revision; (6) user testing; (7) final production. The books and videos developed have been validated by three media experts, two Guidance and Counseling experts, two potential users from Guidance and Counseling Teachers and three cultural experts. The research results revealed that the guidebook for implementing group guidance services using symbolic video modeling to improve students' social and civic harmony was declared suitable for use because it met the elements of excellent product acceptability with high validity. Social harmony which is enhanced through symbolic modeling containing rolled poetry consists of four indicators, namely awareness of cultural diversity, tolerance, self-openness and resolving conflicts constructively. This research only extends to testing media experts, cultural experts, guidance and counseling experts, potential users, and product trials on a small scale. It would be better for future researchers to conduct large-scale experimental research to see the effectiveness of this product.

Keratinases produced by Chryseobacterium proteolyticum FGNn and Pseudomonas aeruginosa GNFx liberated amino acids from poultry feathers

AbstractThe agro-industrial sector generates diverse waste that requires effective handling to mitigate economic loss and pollution. Consequently, this study assessed bacterial isolates from poultry dumpsites for feather decomposition and keratinase production capacity. The protein hydrolysates generated from feather dismemberment by two bacteria identified as Chryseobacterium proteolyticum FGNn (accession no. MW165478) and Pseudomonas aeruginosa GNFx (accession no. MW165479) were profiled for amino acids composition. The biochemical properties of the bacteria-associated keratinases were determined. Initial keratinase production (with percentage feather degradation), demonstrated by the isolates, was 693.63 ± 62.99 U/mL (81%) and 619.09 ± 37.28 (76%) against FGNn and GNFx, respectively. At optimized process conditions, C. proteolyticum and P. aeruginosa extracellular keratinase production was 1756.36 ± 2.57 U/mL at 72 h and 2055.45 ± 50.14 U/mL at 96 h, respectively. Analysis of the feather hydrolysates showed a relatively high abundance of arginine (3.18%) and glycine (3.26%) for FGNn and glutamic acid (6.05%), serine (3.31%), aspartic acid (4.74%), glycine (3.71%), alanine (3.43%), valine (3.09%), and leucine (3.23%) for GNFx. The keratinolytic proteases showed pH and temperature optima of 8.0 and 50°C against FGNn, and 8.0 and 60°C against GNFx. GNFx keratinase was thermostable, displaying a half-life time of more than 60 min at 80°C. In addition, GNFx keratinolytic enzyme was chemical agent tolerant post-treatment. The findings underlined the significance of C. proteolyticum FGNn and P. aeruginosa GNFx as suitable in the valorisation of keratinous biomass. Also, the robust stability profile of GNFx keratinase highlights its prospects in green technology.

Maximizing the value of patient and public involvement in the digital health co-design process: A qualitative descriptive study with design leaders and patient-public partners.

Digital health interventions have enormous potential to support patients and the public in achieving their health goals. Nonetheless, many digital health interventions are failing to effectively engage patients and the public. One solution that has been proposed is to directly involve patients and the public in the design process of these digital health interventions. Although there is consensus that involving patients and the public in collaborative design is valuable, design teams have little guidance on how to maximize the value of their collaborative design work. The main objective of this study was to understand how the value of patient and public involvement in digital health design can be maximized, from the perspective of design leaders and patient-public partners. Using a qualitative descriptive methodology, we conducted semi-structured interviews with 19 design leaders and 9 patient-public partners. Interviewees agreed that involving patients and the public was valuable, however, they questioned if current collaborative methods were optimized to ensure maximal value. Interviewees suggested that patient and public collaborative design can add value through four different mechanisms: (1) by allowing the design process to be an empowering intervention itself, (2) by ensuring that the digital health intervention will be effectively engaging for users, (3) by ensuring that the digital health intervention will be seamlessly implemented in practice, and (4) by allowing patient-public collaborations extend beyond the initial product design. Overall, interviewees emphasized that although collaborative design has historically focused on improving the digital health product itself, patients and the public have crucial insights on implementation planning as well as how collaborative design can be used as its own empowering intervention. The results of this paper provide clarity about the ways that patient and public collaborative design can be made more valuable. Digital health design teams can use these results to be more intentional about their collaborative design approaches.

Development of Arabic-Indonesia Pocket Dictionary to Improve Speaking Skills of Iqro' Stabat Disdit

For elementary school (SD) level students looking for the meaning of a word in a dictionary is not an easy thing, the Arabic dictionary is different from the Indonesian dictionary, because in the Arabic dictionary if you want to look up the meaning of a word then the dictionary generally has to use the base word, sometimes this is something that is still not understood by students, therefore a dictionary is needed that suits the needs of students so that it is easy to use. Apart from teaching subjects like elementary school, it is also added with Arabic lessons, one of which is. The success of the Arabic learning process is greatly supported by learning media. The research approach used in this study is a qualitative research approach. The initial product development in this study was developed based on the ADDIE stages. to develop learning models compared to other instructional designs. As the name implies, the ADDIE model consists of five stages, namely: Analysis, Design, Development, Implementation, Evaluation. The results of the study show that: 1. Analysis is the initial stage of development research by analyzing the curriculum, student needs, Arabic language subjects, and formulating goals. 2. The feasibility of the Arabic language pocket book media on the basic competence of international trade based on the assessment of material experts and media experts in terms of the feasibility aspects of content, language, presentation, and graphics, 3. The response of SDIT Iqro Stabat students with the Arabic language pocket book shows an average acquisition-an average score of 4.23 for small group trials which are included in the Very Eligible category and an average score of 4.06 for field trials which are included in the Eligible category. 4. Arabic language pocket books can increase student learning motivation by 4.04 which is included in the Increased category.

Peningkatan Produktivitas Dengan Metode Green Productivity Pada PT. Bangun Tenera Riau Desa Pantai Raja Kabupaten Kampar

PT Bangun Tenera Riau is a company engaged in the processing of oil palm fresh fruit bunches, located in Pantai Raja Village, Perhentian Raja District, Kampar Regency, Riau Province. The problem faced by PT Bangun Tenera Riau is that the company has not maximally utilized the by-products produced in the form of waste. This research aims to improve the production process by selecting alternative solutions to increase and enhance the initial green productivity index value so that productivity can increase and the impact on the environment can be reduced. The method used in this research is the green productivity method. Based on the environmental performance indicator (EPI) calculation, it is known that the value of biological oxygen demand (BOD) liquid waste has a deviation of -0.63% and an EPI value of -0.16 which exceeds the waste quality standard based on Kep-51 / MENLH / 1995 so that it is necessary to improve the quality of waste through alternative solutions. The alternative solution chosen is an anaerobic biogas reactor and rotating biological contactor (RBC) used to improve waste quality and company productivity. The study's results using the green productivity method obtained an average final total productivity of 1.31 with the initial value of the average productivity in each month being 1.17. The productivity value of the company increased by 0.21 with the efficiency of improving the quality of waste by BOD by 96.81% and converting liquid waste into biogas which is beneficial to the community

Evaluation of Chloride Extraction Rates from Copper Compounds Under Subcritical Conditions

ABSTRACT This paper presents a critical review of the reasons behind the initiation of this project to find a more sustainable, cost efficient, and safer form of chloride extraction that would result in stabilisation of archaeological copper and its alloys with tin and zinc. The imperative has become increasingly strident with cutbacks in funding for museum conservation facilities and with the reduction in staff, leaving less time for routine analyses of traditional immersive washing treatments that could take several years to effect. Owing to the faster oxidation and reduction kinetics of copper, compared with tin and zinc ions, the problems of uncontrolled corrosion of copper alloys in a chloride-rich environment have led to unacceptable levels of decay in heritage collection items. This study looked at the chloride extraction rates under subcritical conditions for both primary and secondary chloride-rich mineral species nantokite, clinoatacamite, and atacamite and determined the impact of changing the solution pH from 8 to 10, while also addressing the impact of temperature. The range of temperatures between 130 and 230°C was assessed at 50°C intervals at both levels of acidity of the leaching liquors. For the nantokite treatment, the formation of a cuprite patina which replaced the waxy-grey initial corrosion products was regarded as a bonus. The nature of the patina and changes in surface textures resulting from the treatment are critically reviewed and a series of recommendations for future work are included in the conclusion.

High-fidelity realization of the AKLT state on a NISQ-era quantum processor

The AKLT state is the ground state of an isotropic quantum Heisenberg spin-1 model. It exhibits an excitation gap and an exponentially decaying correlation function, with fractionalized excitations at its boundaries. So far, the one-dimensional AKLT model has only been experimentally realized with trapped-ions as well as photonic systems. In this work, we successfully prepared the AKLT state on a noisy intermediate-scale quantum (NISQ) era quantum device. In particular, we developed a non-deterministic algorithm on the IBM quantum processor, where the non-unitary operator necessary for the AKLT state preparation is embedded in a unitary operator with an additional ancilla qubit for each pair of auxiliary spin-1/2’s. Such a unitary operator is effectively represented by a parametrized circuit composed of single-qubit and nearest-neighbor CX gates. Compared with the conventional operator decomposition method from Qiskit, our approach results in a much shallower circuit depth with only nearest-neighbor gates, while maintaining a fidelity in excess of 99.99% with the original operator. By simultaneously post-selecting each ancilla qubit such that it belongs to the subspace of spin-up |↑>, an AKLT state can be systematically obtained by evolving from an initial trivial product state of singlets plus ancilla qubits in spin-up on a quantum computer, and it is subsequently recorded by performing measurements on all the other physical qubits. We show how the accuracy of our implementation can be further improved on the IBM quantum processor with readout error mitigation.

Critical mass: the creation of Pajarero/Birder communities in Mexico for citizen science

ABSTRACT Birding (pajareo) precedes the field of citizen science by decades, if not centuries. However, by being incorporated into institutional programs and digital platforms [Invernizzi, N. 2020. “Public Participation and Democratization: Effects on the Production and Consumption of Science and Technology.” Tapuya: Latin American Science, Technology and Society 3 (1): 227–253. https://do.org/10.1080/25729861.2020.1835225], birding has been inscribed into the logic of data-intensive science [Scroggins, M. J., and I. V. Pasquetto. 2020. “Labor Out of Place: On the Varieties and Valences of (In)Visible Labor in Data-Intensive Science.” Engaging Science, Technology, and Society 6:111–132. https://do.org/10.17351/ests2020.341], with the premise of increasing the number of volunteers to accumulate more and more data. The history of these practices in Mexico is very recent, dating back only about 15 years. The explosion in the number of practitioners since then has been largely the product of institutional arrangements and top-down initiatives carried out by Mexican government environmental agencies. Building on recent STS approaches to public participation that conceive citizen science as a situated and contextual phenomenon, I propose that public policies can be legitimately used to create publics. From the study of interviews, visual materials, participant observation in birding field trips, and other ethnographic materials, I recover the different stories that have led to the creation of brigades, groups, and observation clubs in Mexico. I argue that this approach allows us to go beyond normative positions and present a much more complex reality than the mere instrumental relationship between institutions and communities.

A physics-guided eXtreme gradient boosting model for predicting the initial productivity of oil wells

The initial productivity of oil wells is an important index in oilfield development. Due to the nonlinear relationship among the numerous affecting factors of productivity, productivity prediction methods based on seepage theory are difficult to characterize this nonlinear relationship. The machine learning method provides a novel theory to solve this problem. However, the data-driven machine learning method neglects the physical-based seepage theory. For balancing the advantage of the seepage model and the data-driven model, the productivity formula was used to guide the machine learning algorithm for achieving nonlinear regression in this study. Therefore, an innovative physics-guided eXtreme Gradient Boosting (XGBoost) trees algorithm was proposed to predict the initial productivity. The productivity formula was employed as the physical constraint and combined with the mean-square error (MSE) loss function of the XGBoost algorithm. A hyperparameter was introduced to balance the productivity formula and the MSE formula for constructing this adaptive physics-guided loss function. Moreover, the random subsampling cross-validation approach was adopted to train the XGBoost model. The grid search approach was introduced to optimize the hyperparameters of the model. The results show that based on the numerical simulator data, the initial productivity prediction accuracy of physics-guided XGBoost was verified as 94.67%, which was higher than the completely data-driven model. Moreover, the robustness of the novel adaptive physics-guided loss function for improving forecasting accuracy had been validated with sample sizes between 50 and 20000. By introducing the physics-guided sampling process and loss function, the applicability of the XGBoost algorithm has been extended to small sample conditions. Furthermore, the practical accuracy of physics-guided XGBoost was verified as 84.74% by 162 oil wells in the Penglai oilfield. Therefore, the application value of combining the physical knowledge with the XGBoost model has been confirmed in oilfield situations.

Formation, Evolution, and Antioxidant Activity of Melanoidins in Black Garlic under Different Storage Conditions.

Melanoidins (MLDs) are formed through the reaction of carbonyl compounds and amino compounds in the Maillard reaction (MR) during the heating or storage of food. In this study, the formation, chemical composition, and structural characteristics of black garlic (BG) MLDs stored at different temperatures (4 °C, 20 °C, and 35 °C) over a period of 6 months were investigated. The initial products of the MR formed more often at 4 °C and 20 °C, while higher temperatures (35 °C) promoted the reaction in the middle and late stages of the MR. The higher temperature promoted an increase in molecular weight and MLD content, which can be attributed to the increase in protein and phenolic content. Elemental analysis confirmed an increase in nitrogen (N) content and the continuous incorporation of nitrogen-rich substances into the skeleton. Amino acids, particularly aspartic acid and threonine, were the primary N-containing compounds involved in MLD formation. Additionally, the infrared analysis revealed that the changes in MLDs during storage were characterized by amide I and amide II groups. The MR enhanced the yields of heterocyclic compounds (from 56.60% to 78.89%), especially that of O-heterocyclic compounds, at the higher temperature according to Py-GC-MS analysis. Furthermore, the higher temperature enhanced the molecular weight, maximum height, and roughness of MLDs compared to the control. The antioxidant ability of MLDs was positively correlated with storage temperatures. In summary, temperature had an impact on the formation, evolution, and antioxidant activity of MLDs.

PENGEMBANGAN MEDIA AJAR BERBASIS ARTIFICIAL INTELEGENCE PADA MATA KULIAH EVALUASI PEMBELAJARAN MATEMATIKA

This research is a development research (R&D). This study aims to develop learning media based on Artificial Intelligence (AI) in mathematics learning evaluation courses. The research was developed using the ADDIE model (analysis, design, development, implementation and evaluation). The media was developed by utilizing several AI tools, namely ChatGPT, Fliki, Toonme and D-ID. Experts provide an assessment of AI-based media with an average rating of Good. Media gets 78% Good in terms of appearance, 85% in a very good category in terms of use, and 80% in a good category in terms of presentation of material. Based on the assessment of material experts, the products that have been developed get 79% in the good category in terms of the suitability of the teaching materials and the assessment of the coherence of the material is 80% in the good category. Based on the assessment of linguists, the developed product received an 82% rating in the very good category in terms of the language used. A score of 78% is in a good category in terms of the pronunciation of the language in audio and a score of 79% is in a good category in language selection. Based on the results of the validation and assessment of experts, small group trials, large group trials and then revisions to the initial media products developed, the Artificial Intelligence-based learning media for mathematics learning evaluation courses is declared feasible to be used and exploited in the field.

Enhancing scalability and economic viability of lignocellulose-derived biofuels production through integrated pretreatment and methanogenesis arrest

The pursuit of affordable biofuels necessitates continuous refinement of valorization strategies, focusing on cost-effective feedstocks, accessible bioprocessing, and high-quality products. High energy input required during various stages, including pretreatment, post-pretreatment, and methanogenesis arrest, impeded the economic lignocellulose-derived biofuels production from anaerobic digestion (AD). Addressing this challenge, an upstream process integrating synergistic alkali pretreatment and arrested AD was proposed. Results demonstrated that an optimum reactor pH 10 yielded a volatile fatty acids (VFA) titer of 3.6 gCOD/L, only 23% lower than using methanogenesis inhibitor. The study further explored the interplay between initial pH, cell viability/functionality, and VFA production by assessing cell viability and cell population demographics. This integrated approach demonstrated a VFA yield of 364 gVFA/kgTSsubstrate at a cost of just USD 0.2/kgVFA, encompassing post-pretreatment and methanogenesis arrest, which underscores the viability of combining pretreatment and methanogenesis arrest for cost effective and scalable biofuels production.

Numerical Analysis on Gas Production and Geomechanical Responses of Natural Gas Hydrate Reservoirs.

Natural gas hydrate (NGH) has attracted considerable global attention as a promising energy resource in recent years. To acquire valuable insights into regarding the interplay between mechanical properties and production outcomes during the production, in this study, a fully coupled thermo-hydro-mechanical-chemical (THMC) model based on the geological features of reservoirs in the Shenhu area of the South China Sea (SCS) was developed to analyze the response characteristics of various physical fields within the reservoir during the exploitation. Furthermore, the study examined the influence of mechanical behavior on hydrate exploitation and investigated the effects of varying initial hydrate saturation and seawater depth on production efficiency and reservoir deformation. The simulation results indicated that neglecting the impact of solid mechanics in the analysis of hydrate productivity can result in overestimated results, particularly during the initial production stage. Reservoirs with higher hydrate saturation experience lower initial production rates due to the influence of permeability and capillary force. Moreover, reservoirs with high hydrate saturation exhibit greater compression but lower wellhead subsidence during the long-term development. The impact of seawater depth on production capacity primarily arises from the pressure's influence on the gas-water ratio, where greater seawater depth corresponds to increased reservoir compression and wellhead subsidence.

Loss of beef during primary production at Swedish farms 2002–2021

Loss of animals is a considerable waste of resources in the meat supply chain, where quantitative data are scarce but critical for guiding improvements. In this study, we used material flow analysis to track the amount of beef diverted away from the food supply chain at the farm level. The beef losses (absolute and as the proportion of yearly initial production) were estimated from data on assisted and unassisted deaths of cattle on Swedish farms obtained from the central register of bovine animals for 2002–2021 combined with official statistics on slaughter weight. The fallen animals were grouped according to age, sex and breed, to enable estimations of the lost amount of carcass weight, both in total and per animal group. The yearly loss during primary production 2017–2021 was on average 13,000 ton carcass weight, or 8.5% of the initial production. No decreasing trend for the loss rate could be determined after 2015, when the Agenda 2030 target 12.3 (Halved food waste and reduced early losses) was introduced. Female dairy breeds showed greater beef losses than dairy males or beef breeds and crossbreeds of both sexes, and their beef losses mostly occurred at 4–5 years of age, thus constituting the hot spot group for lost beef. The results can serve as a base for directed reduction efforts.

Evaluasi Kecukupan Panas dan Pengembangan Proses Alternatif dalam Sterilisasi Komersial Jamur Kancing dalam Kaleng

. This research aimed to evaluate the adequacy of heat treatment and redesign the commercial sterilization process for canned button mushrooms to ensure that the product meets the minimum sterilization requirement without undergoing excessive processes. The study conducted tests on heat distribution and penetration, calculated the sterilization value (F0) using the trapezium and Ball methods, and designed an alternative sterilization process to avoid excessive procedures. The sterilization process for canned mushrooms, with a can dimension of 300x407, involved a temperature of 132°C for 16 minutes, resulting in an F0 value of 161.7 minutes. This value far exceeds the required minimum F0 value. To optimize the process, an alternative sterilization procedure was developed. It involved a temperature of 126°C, a process time of 10 minutes, and an initial product temperature of 40–50°C. This alternative process yielded an F0 value of 10 minutes. Furthermore, additional alternative process conditions were designed, with considerations to various process times (Pt), initial temperatures (Ti), retort temperatures (TR), and F0 values.

Healthy shopping dynamics: The healthiness of sequential grocery choices

Improving the healthiness of diets can be realized by replacing unhealthy with healthier product alternatives when shopping for groceries. For this strategy to be effective, shoppers need to consistently make healthier choices. However, shoppers may end up balancing the healthiness of their choices throughout the shopping trip, (partly) offsetting the benefits of a healthy product choice (e.g., low-fat milk) by an unhealthy subsequent choice (e.g., sugary cornflakes). Across two studies, one study with purchase data from a brick-and-mortar supermarket and one online experimental study, we empirically demonstrate that the relative healthiness of an initial product choice is indeed inversely related to the relative healthiness of the subsequent choice, regardless of the category of both products. That means: a relatively healthy choice is followed by a relatively unhealthier choice, and vice versa. Furthermore, the strength of this balancing effect differs depending on the nature of the product category; the dynamic effect is less pronounced when subsequently choosing within a vice (vs. virtue) product category. In the brick-and-mortar supermarket, the dynamics also become less pronounced as the shopping trip progresses. These findings contribute to literature on in-store decision-making and within-trip dynamics, and underscore the need for retailers to have a thorough understanding of these healthy shopping dynamics in order to effectively promote healthier baskets in support of the growing demand for healthy diets.

Chemical decontamination of methamphetamine and ephedrine using household hypochlorite bleach

Hypochlorite bleach is an easily accessible, commonly used cleaning product. Methamphetamine and ephedrine hydrochloride react rapidly with 3.5 g/L (1:8 dilution of a commercial household bleach) and 21 g/L (2:1 dilution) solutions of sodium hypochlorite bleach in water, with each reaction being complete within 5 min of mixing. The major methamphetamine reaction product was identified as N-chloromethamphetamine which was reliably quantified by dechlorination using a sulfite quench prior to sample extraction and analysis by gas chromatography – mass spectrometry (GC–MS). The initial product from ephedrine was benzaldehyde, and this then formed benzoic acid as a second-generation product in the 3.5 g/L sodium hypochlorite bleach solution.N-Chloromethamphetamine was observed to persist in solution for several hours with minor formation of benzaldehyde and N-chloro-1-phenylpropan-2-imine, a proposed second-generation product from N-chloromethamphetamine, also detected. Assessment of further N-chloramine reaction products will aid in our ability to estimate exposure risks to those attempting drug remediation using hypochlorite bleach. These observed products can also be used as potential forensic markers of the use of a property for illicit activity if bleach has been used in an attempt to decontaminate the location.

Solar Power Generator as an Alternative Energy Source for the Propeller Driver Motor

Solar Power Generation is one of the renewable energy modes currently being extensively developed. This is due to environmental issues caused by non-environmentally friendly fossil fuel sources. The purpose of this research is to support efforts in reducing the use of fossil fuels by designing a model of an electric main engine using Solar Power Generation (PLTS) and understanding the working system of this design. The research method used is the Research and Development method, consisting of 10 stages. These stages include information gathering, product planning, initial product form development, initial testing, initial revisions, main testing, major revisions, testing and validation, final revisions, and product implementation. The results of this research include designing the model, starting with assembling electronic and mechanical components and integrating them into the ship's body as a system. The working system of this design involves converting solar energy into electrical energy, which is then used as the energy source to drive the ship's propeller.