Operational Difficulties Research Articles

Fundamental drying and agglomeration experiments with bio-fraction and refuse derived fuel for the development of pyrolysis reactor feed.

The EU's circular economy concept necessitates increasing the recycling ratio of municipal solid wastes. There are many existing mechanical-biological processing plants in Hungary for the preparation of residual municipal solid wastes (RMSWs). The two most important products of these plants are the bio-fraction and the refuse derived fuel (RDF). Currently, there are problems with both of these material streams in Hungary, since most of the bio-fraction is still landfilled, and the local thermal utilisation of the RDF has not been implemented yet. The high moisture content of the produced bio-fraction and RDF causes difficulties for the downstream operations; therefore, there is recent engineering interest in drying and agglomeration of these materials. The authors have carried out systematic and parallel drying and briquetting experimental series to study the effect of the material, material composition, mass (volume or surface) of the material, particle size distribution and pre-treatment with a cutting mill on drying intensity in a 1 m3 oven and their effect on briquettability by a laboratory briquette press. The initial slope of the relative moisture loss as function of time was determined. Process engineering design methods of convective hot air-drying can be further developed taking into account the research results. Results can be used for the design of the feed of a pyrolysis reactor once reactor experiments have provided the optimal feed requirements.

Source-Separated Industrial Wastewater Is a Candidate for Biogas Production through Anaerobic Digestion

Anaerobic digestion is a potential treatment for industrial wastewater that provides valuable end-products, including renewable energy (biogas). However, waste streams may be too variable, too dilute at high volumes, or missing key components for stable digestion; all factors that increase costs and operational difficulty, making optimisation crucial. Anaerobic digestion may benefit from process intensification, particularly the novel combination of high-strength source-separated wastewater to minimise volume, together with the use of biosolids biochar as a chemical and microbial stabiliser. This study investigates the stability, yield, and microbial community dynamics of the anaerobic digestion of source-separated industrial wastewater from a food manufacturer and a logistics company, using biosolids biochar as an additive, focusing on gas and volatile fatty acid (VFA) production, process stability, and the microbial community using bench-scale semi-continuous reactors at 30- and 45-day hydraulic retention time (HRT). While gas yields were lower than expected, stability was possible at high HRT. Methane production reached 0.24 and 0.43 L day−1 per litre reactor working volume at 30- and 45-day HRT, respectively, despite high VFA concentration, and was linked to the relative abundance of Methanosarcina in the microbial community. Interactions between substrate, VFA concentration, and the microbial community were observed. Biochar-assisted anaerobic digestion holds promise for the treatment of source-separated wastewater.

What drives construction SMEs on CSR implementation during economic uncertainty?

World uncertainty is currently at an exceptionally high level, leading to difficulties in business operations. This phenomenon raises questions about the necessity of corporate social responsibility (CSR) initiatives for vulnerable organizations such as small and medium-sized enterprises (SMEs) as they may deprioritize CSR to focus on surviving. The review of previous studies highlighted a limited theoretical understanding of CSR that existed during such challenging economic periods. This study aims to bridge this research gap by investigating the driving forces that motivate construction SMEs to implement CSR during economic uncertainty. Through a combination of literature review, semi-structured interviews, and hybrid fuzzy Decision-Making Trial and Evaluation Laboratory-Analytic Network Process methods, 13 drivers for CSR were identified and categorized into four clusters: human resources benefit, market pressure, organizational reputation, and financial benefit. Human resources benefit was recognized as the most influential cluster, and employee commitment and loyalty was the most critical CSR driver. This study contributes to the body of knowledge by theoretically explaining the prioritization of drivers to CSR performance regarding their interrelationships.

Preliminary thermal performance characterization of a flexible separate heat pipe used for the tracking-type photovoltaic/thermal system

In the solar heating field, the separate heat pipe-based photovoltaic/thermal technology can improve the comprehensive utilization efficiency of solar energy and reduce the maintenance difficulty in long-term outdoor operation by preventing freezing and scaling problems. Its promotion and application are of great significance for reducing fossil energy consumption and carbon emissions, and thus have attracted much attention. However, the performance of conventional photovoltaic/thermal modules is limited by their frame shadow due to the insulation demand, which leaves plenty of room for overall efficiency gains. To solve this problem, a novel separate heat pipe-based photovoltaic/thermal system is proposed by introducing a dual-axis tracking method through a flexible separate heat pipe and side-altitude inclination. To preliminarily characterize the thermal performance of the flexible separate heat pipe in dual-axis tracking conditions, an indoor experimental platform of the flexible separate heat pipe using the solar collector and finned-tube heat exchanger in the water tank as the evaporator and condenser was set up. The effects of side inclination angle, altitude angle of the solar collector and solar irradiance on the thermal efficiency, mass flow rate, and thermal resistance of the system are investigated in detail. The experimental results show the system can generally maintain effective heat transfer in side inclination states, with thermal efficiency mostly ranging from 44.68% to 86.12%. The proposed flexible separate heat pipe is qualified for the dual-axis tracking of photovoltaic/thermal system and shows great potential in improving the utilization of solar energy.

Effective prevention of structure II gas hydrate formation using the newly synthesized kinetic inhibitors

Gas hydrate deposition is a complex issue with significant implications for the oil and gas industry. The formation of solid gas hydrates in the hydrocarbon transportation pipelines leads to production disruptions and potentially even complete blockages, resulting in huge financial losses and operational difficulties. For over two decades, kinetic gas hydrate inhibitors have played a crucial role in preventing the formation of gas hydrates within the flow lines of oil and gas production. They directly influence the kinetics of hydrate formation, hindering nucleation and slowing down crystal growth. In this study, five new waterborne polyurethanes (WPUs) with varying degrees of hydrophobicity as inhibitors for cubic structure II gas hydrates were synthesized and tested using rocking cells and differential scanning calorimetry. The synthesis of WPUs involved the reaction between dialkylamines (diethyl, dipropyl, dibutyl, dibenzyl, and dioctyl) and glycidol under mild conditions. All WPUs effectively prevented gas hydrate formation, and a correlation between their efficiency and the alkyl chain length was observed. The inhibitory efficacy of WPUs increased with the extension of the alkyl chain from ethyl to butyl. WPU-DBuA, featuring butyl groups, exhibited the highest inhibition activity. It provided a subcooling temperature of 12.9 and 15.6 °C at 0.25 and 0.5 wt%, respectively, surpassing commercial samples, such as Luvicap EG and Luvicap 55 W. Additionally, the solutions containing 1 and 2 wt% of WPU-DBu exhibited maximum subcooling temperatures of 16.2 °C and 16.7 °C, respectively, which correspond to a 79.7 % and 85.4 % reduction in gas uptake during hydrate growth compared to pure water. However, the inhibitory power of WPUs diminished with larger alkyl (dioctyl) or aromatic groups (dibenzyl), indicating that dibutyl represents the optimal alkyl length for achieving maximum performance. Moreover, WPUs demonstrated a reduction in hydrate conversion under static conditions, signifying their efficiency when the flow is stopped. WPUs lowered the onset temperature of hydrate formation from 3 °C in pure water to temperatures below −12 °C. Thus, WPUs demonstrated a remarkable ability to prevent the formation of structure II gas hydrates, even under high subcooling conditions. Additionally, WPU-DBuA exhibits a considerable degree of biodegradability, as evidenced by its biodegradation level of 44 %, suggesting that it has the potential to break down more easily in the environment compared to Luvicap 55 W. This research contributes to a deeper understanding of the structure–property relationships of KHIs. This can facilitate the development of more effective and eco-friendly inhibitors, which helps address environmental concerns associated with using KHIs in the oil and gas industry.

Cost-Effective digital twin Design for entertainment Enterprise’s through Machine learning

The backbone of the Indian economy, Micro, Small, and Medium Enterprises (MSME) players provide rural residents with steady income and long-term employment possibilities. Due to antiquated machinery, ineffective procedures, outdated manufacturing and business methods, and a severe lack of funds to cover their capital and operating costs, Indian MSME operators are finding it difficult to thrive in the cutthroat market of today. Small and medium-sized enterprises (SMEs) mistakenly believe that the industry 4.0 ecosystem, which encompasses numerous developing technologies, is exclusively intended for larger corporations. However, SMEs can effectively leverage these technologies to tackle their operational difficulties. This research study offers a unique, purpose-built Industry 4.0 solution to help MSME participants in the Software as a Service (SaaS) model save maintenance costs. With just monthly operating costs, this system provides a scalable and incredibly economical approach that does not require any capital expenditures. This solution includes emerging technologies such as IoT, cloud, analytics, and mobile applications. This solution has been implemented in three MSME businesses from Chennai, India and achieved 84% decrease in maintenance cost.

Design, Optimization, and Modeling of a Hydraulic Soft Robot for Chronic Total Occlusions.

Chronic total occlusion (CTO) is one of the most severe and sophisticated vascular stenosis because of complete blockage, greater operation difficulty, and lower procedural success rate. This study proposes a hydraulic-driven soft robot imitating the earthworm's locomotion to assist doctors or operators in actively opening thrombi in coronary or peripheral artery vessels. Firstly, a three-actuator bionic soft robot is developed based on earthworms' physiological structure. The soft robot's locomotion gait inspired by the earthworm's mechanism is designed. Secondly, the influence of structure parameters on actuator deformation, stress, and strain is explored, which can help us determine the soft actuators' optimal structure parameters. Thirdly, the relationship between hydraulic pressure and actuator deformation is investigated by performing finite element analysis using the bidirectional fluid-structure interaction (FSI) method. The kinematic models of the soft actuators are established to provide a valuable reference for the soft actuators' motion control.

Research on product design of FAHP bone marrow aspiration needle

Bone marrow aspiration is a crucial medical procedure to obtain bone marrow samples for diagnosis and treatment. However, traditional bone marrow aspiration needles face several challenges such as operational difficulties, inadequate sample acquisition, and patient discomfort. To address these issues, we aimed to design a bone marrow aspiration needle product by using fuzzy analytic hierarchical process (FAHP). The FAHP method was used to identify key factors in the design of the bone marrow aspiration needle, including technicality, usage, and application characteristics. The importance weights and priorities of each factor were determined through questionnaires and interviews with experts. A new bone marrow aspiration needle product was developed based on the results of the FAHP. The new product design considers the weights and priorities assigned to key factors, resulting in improved convenience during operation and a higher success rate of sample acquisition. This was achieved by optimising the structure and material selection of the needle. This study presents a novel bone marrow puncture needle product that effectively integrates the importance and priority of the key factors. It successfully enhances operational performance and patient experience, thereby offering an innovative solution to improve the success rate and therapeutic effect of bone marrow punctures.

The 5 Ws of Ambulatory Blood Pressure Monitoring.

Blood pressure (BP) measurement is affected by multiple variables which influence clinical management decisions and patient outcomes. Around 24-hour ambulatory blood pressure monitoring (ABPM) avoids incorrect diagnosis of hypertension (HT), and unnecessary treatment and provides the best prediction of cardiovascular (CV) risk. Clinically important phenotypes of HT such as masked HT (masked HT), white coat HT (white coat HT), and nocturnal HT (nocturnal HT) may be missed by not incorporating ambulatory BP monitoring in practice. However, lack of device availability, operational difficulties, and cost remain barriers to its widespread acceptance in India. In this review, we discuss the when, what, who, why, and where (5Ws) relevant to ABPM measurement.

PENGGABUNGAN KRIPTOGRAFI RIVEST SHAMIR ADLEMAN (RSA) DAN ADVANCED ENCRYPTION STANDARD (AES) PADA APLIKASI PENGIRIM E-MAIL

One of the most commonly used communication tools is e-mail. Messages sent via e-mail can contain confidential information, security measures are needed for confidential messages sent via e-mail. Cryptography is one of the security measures that can be taken. Based on the types of keys, there are two types of cryptography namely symmetric and asymmetric. Symmetric cryptography uses the same key in the encryption and decryption process, while asymmetric cryptography uses different keys. Symmetric keys can be encrypted by asymmetric keys to make the transmission of secret keys more secure. The symmetric and asymmetric cryptography chosen are AES (Advanced Encryption Standard) and enhanced RSA (Rivest Shamir Adleman). RSA cryptography is known for its strong security based on the difficulty of exponential and factorization operations, while AES cryptography is a secure cryptography standard that has a relatively fast computation time. An e-mail application to send secret messages using combined cryptography algorithm constructed using Python programming language.

DEVELOPMENT OF UNIFIED UNIT DESIGN FOR SEPARATION OF HIGHLY MINERALIZED WATER-METHANOL MIXTURE

None of the commodity industries generates as much excitement and profit as oil and gas, which are the main energy carriers. The ability to utilize these key products and their reserves, to hold the strings of business in these areas, determines the path to economic prosperity and the choice of political and economic strategy of the state.The Far North is an area larger than several European countries. It is characterized by extreme climatic conditions, a quarter of all foreign currency revenues to the state budget of Russia comes from this region. 20% of the world’s gas and 90 % of Russian gas and oil are produced here annually. Moreover, the Far North is not only a powerful raw material base of the country today, it is also a kind of guarantor of energy security of the state for many years to come: a quarter of all explored world reserves of natural gas and oil are concentrated here.Resource extraction in the Far North is complicated by a number of external factors, such as low temperatures, difficulties in delivery, installation of equipment at the site, as well as in the operation and repair of process equipment, which in turn leads to new requirements for the design of equipment used for oil and gas production. This paper describes the developed concept of a small-size separation unit for highly mineralized water-methanol mixture (hereinafter referred to as WMM), which is achieved by adopting a number of new technological solutions. The paper also describes the developed methodology of designing a small-size Navy separation plant, which allows to reduce the number of economic costs caused by difficulties in transportation, installation and operation.

A Knowledge-Guided Intelligent Analysis Method of Geographic Digital Twin Models: A Case Study on the Diagnosis of Geometric Deformation in Tunnel Excavation Profiles

It is essential to establish a digital twin scene, which helps to depict the dynamically changing geographical environment accurately. Digital twins could improve the refined management level of intelligent tunnel construction; however, research on geographical twin models primarily focuses on modeling and visual description, which has low analysis efficiency. This paper proposes a knowledge-guided intelligent analysis method for the geometric deformation of tunnel excavation profile twins. Firstly, a dynamic data-driven knowledge graph of tunnel excavation twin scenes was constructed to describe tunnel excavation profile twin scenes accurately. Secondly, an intelligent diagnosis algorithm for geometric deformation of tunnel excavation contour twins was designed by knowledge guidance. Thirdly, multiple visual variables were jointly used to support scene fusion visualization of tunnel excavation profile twin scenes. Finally, a case was selected to implement the experimental analysis. The experimental results demonstrate that the method in this article can achieve an accurate description of objects and their relationships in tunnel excavation twin scenes, which supports rapid geometric deformation analysis of the tunnel excavation profile twin. The speed of geometric deformation diagnosis is increased by more than 90% and the cognitive efficiency is improved by 70%. The complexity and difficulty of the deformation analysis operation are reduced, and the diagnostic analysis ability and standardization of the geographic digital twin model are effectively improved.

Distributed Energy Resource Deployment to Mitigate Adverse Effects of High EV Penetration in Unbalanced Distribution System by Analytical Sensitivity-Based Optimization

The rapid integration of electric vehicles (EVs) into distribution systems in response to environmental concerns poses challenges for power system operators. This article addresses the operational difficulties faced by unbalanced distribution systems (UDS) when incorporating three-phase EV loads. We propose a novel method for supporting EV integration and enhancing UDS operational indicators, including voltage unbalance, bus voltage stability, and bus voltage deviation. Our approach utilizes analytical loss sensitivity index (ALSI)-based meta-heuristic wild horse optimization for the optimal allocation of distributed energy resources (DERs) and capacitor bank during EV load connections. The ALSI is employed to identify potential DER locations, streamlining the computation process and reducing search space. Tested on a modified 123-bus UDS, the proposed method demonstrates a 76.71% reduction in total active power loss and a 96.43% reduction in total voltage deviation. The results underscore the effectiveness and applicability of the proposed approach. While showcasing promising outcomes, the article also discusses the potential limitations and implications for practical implementation.

Allograft Model of Aortic Arch Segment Grafting to Abdominal Aorta Through End-to-Side Anastomosis in Mice

The mouse aortic transplantation model is a valuable tool for investigating the mechanisms of atherosclerosis regression, but few laboratories can generate it due to the operation difficulty, especially for the style of end-to-side anastomosis, which facilitates syngeneic heterotopic transplanting a plaque-rich aortic arch into the abdominal aorta. Here we provide a modified protocol for generating this allograft model, which is capable of overcoming several critical surgical challenges such as separating a longer abdominal aorta segment, reducing bleeding and thrombosis, optimizing aortotomy, and improving end-to-side anastomosis to guarantee a potent graft. By transplanting plaque-rich aortic arches into the abdominal aorta of wildtype mice, a high operation success rate (over 90%) was noted with aortic clamping time under 60 min, the graft potency was satisfactory evidenced by examinations of micro-CT, ultrasound, and lower limb blood flow measurement, while a significant atherosclerosis regression was observed in the grafts at 1 week after transplantation.Graphical

Research on Integrated Design of Hardware and Software for Needle-Free Insulin Injection Systems for the Elderly

With the accelerating trend of global population aging, the incidence of diabetes among the elderly continues to rise. Insulin injection, as one of the key methods for treating diabetes, has disadvantages like high operation difficulty and poor compliance among elderly patients in actual application. This research conducts in-depth investigations on the characteristics of elderly diabetic patients, identifying key difficulties they experience in using needle-free insulin injection products. On this basis, a design solution covering overall interaction reconfiguration and function optimization is proposed, with needle-free insulin injectors as the core to develop an integrated support system tailored for the elderly. Results demonstrate that this optimized design exhibits significant effectiveness in enhancing the device experience of elderly patients and improving compliance. The innovation of this research lies in approaching the needle-free injection issue from an overall medical-patient perspective, providing a new solution strategy to meet elderly diabetic patients’ device needs, with extensive potential for promotion and application.

Member separation and deformation recognition of spatial grid structures in-service

Bending deformation of members in spatial grid structures is a typical damage threatening structural safety. Conventional methods of deformation measurement have difficulty in detection member selection, high-altitude operation, or systematic error elimination. And reverse modeling technology for deformation detection is mostly utilized in entire structures or laboratory scenes. In this study, two kinds of member separation algorithms are developed based on point cloud registration and point cloud features respectively, both of which are suitable for engineering situations of insufficient point cloud density and multiple noise sources. The deformation recognition algorithm for members is improved accordingly with double judgment conditions. A field test has been carried out in a Sports Center Stadium in Guangzhou province. 7045 members are identified, and 29 crooked members are eventually recognized. The results demonstrate that the proposed algorithms can improve the efficiency of member separation and deformation recognition, and assist the monitoring and assessment of spatial grid structures in-service.

Application of Caenorhabditis elegans in Neurotoxicology

Neurotoxicological studies usually use mammals similar to humans as model animals for research. Although the high similarity with humans makes it a good choice, the complicated nervous system and the difficulty of feeding and operation have become unfavorable conditions in the research. And the longer life span greatly extends the research cycle to study long-term toxicity. The problem can be solved using Caenorhabditis elegans (C.elegans)as experimental animals. C.elegans have a fast growth rate, short research period, and easy culture and preservation compared with mammals used to study Neurotoxicology. It has the advantages of strong genetic stability, gene conservation, small individual differences, simple structure, and easy observation and operation. So, C. elegans is an ideal model for long-term toxicity study.

Tampa Difficulty Score: a novel scoring system for difficulty of robotic hepatectomy

BACKGROUNDDifficulty scoring systems (DSS) have been established for laparoscopic hepatectomy and serve as useful tools to predict difficulty and guide preoperative planning. Despite increased adoption of robotics and its unique technical characteristics compared with laparoscopy, no DSS currently exists for robotic hepatectomy. We aim to introduce a new DSS for robotic hepatectomy. METHODS328 patients undergoing a robotic hepatectomy were identified. After removing the first 24 major and 30 minor hepatectomies using CUSUM analysis, 274 patients were included in this study. Relevant clinical variables underwent linear regression using operative time and/or estimated blood loss (EBL) as markers for operative difficulty. Score distribution was analyzed to develop a difficulty-level grouping system. RESULTSOf the 274 patients, neoadjuvant chemotherapy, tumor location, size, type, extent of parenchymal resection, need for portal lymphadenectomy, and need for biliary resection with hepaticojejunostomy were significantly associated with operative time and/or EBL. They were utilized to develop the difficulty scores from 1-49. Grouping system results were: Group 1 (Less Demanding/Beginner): 1-8 (n=39), Group 2 (Intermediate): 9-24 (n=208), Group 3 (More Demanding/Advanced): 25-32 (n=17), and Group 4 (Most Demanding/Expert): 33-49 (n=10). When stratified by group, age, prior abdominal operation, Child-Pugh score, operative duration, estimated blood loss, major resection, 30-day mortality, 90-day mortality, and length of stay were significantly different among the groups. CONCLUSIONSIn addition to established variables in laparoscopic systems, new factors such as the need for portal lymphadenectomy and biliary resection specific to the robotic approach have been identified in this new robotic DSS. Internal and external validation are the next steps in maturing this robotic DSS.

Analisis Kesulitan Belajar Matematika pada Materi Penjumlahan dan Pengurangan di MIs Yayasan Azis Al Akbar

Many students at Azis Al Akbar Elementary School are having trouble understanding addition and subtraction in basic arithmetic. This research aims to identify the difficulties in learning mathematics among lower-grade students. The researcher used a qualitative descriptive approach. The study subjects were 13 students, including 2 boys and 10 girls. Data was collected through interviews, tests, and document studies. The results showed that: 1) students' reading abilities are still lacking, making it difficult for them to understand, 2) difficulties in counting more than two digits are still low, 3) difficulties in understanding addition and subtraction operations, and 4) students' lack of interest in learning due to minimal parental encouragement. Based on these findings, the researcher hopes that teachers can teach and introduce addition and subtraction operations to students so that they can understand them.

Public participation in human genome editing research governance: what do scientists think?

Within the numerous policy and governance recommendations for human genome editing research, anticipatory public engagement seems universally agreed upon as a vital endeavor. Yet it is unclear whether and how scientists whose research involves genome editing see value in engaging the public in discussions of genome editing research governance. To address this question, we interviewed 81 international scientists who use genome editing in their research. The views of our scientist interviewees about public engagement occupied a broad spectrum from enthusiastic support to strong skepticism. But most scientists' views landed somewhere in the middle, seeing public engagement as merely informing the public about the science of genome editing. We argue that such a stance reflects the traditional "knowledge-deficit model." Beyond addressing the operational difficulties of public engagement, many scientists' adherence to the deficit model is a deeper barrier that needs to be addressed if public engagement is to occur and be successful.