Insufficient Flow Research Articles

A geographic routing protocol based on trunk line in VANETs

A Trunk Line Based Geographic Routing(TLBGR) protocol in Vehicular Ad-hoc Networks (VANETs) is proposed in this paper to solve the problem of data acquisition in the traditional trunk coordinated control system. Because of the characteristics of short communication time and high packet loss among vehicles, the vehicles entering the trunk lines can not transmit their information to the trunk coordinated control system stably. To resolve this problem, the proposed protocol uses the trunk lines’ traffic flow and the surrounding road network to provide a real-time data transmission routing scheme. It takes into account the data congestion problem caused by the large traffic flow of the main roads, which leads to the corresponding increase of the information flow of the section and the package loss, and the link partition problem caused by the insufficient traffic flow, which makes the vehicles have to carry and relay information thus increasing the transmission delay. The proposed TLBGR protocol can be divided into two stages: the next-intersection selection, and the next-hop selection in the chosen path between the current and next intersections. Simulation results show that, compared with other IoT routing protocols including Greedy Perimeter Stateless Routing (GPSR), Ad-hoc On Demand Vector (AODV), and Q-AODV, the TLBGR protocol has better performance in aspects of end-to-end delay, delivery rate, and routing cost under the scenario of urban traffic trunk lines. The TLBGR protocol can effectively avoid data congestion and local optimum problems, increase the delivery rate of data packets, and is therefore suitable for the routing requirements in this application scenario.

Исследование кавитации в каналах форсунок систем пожаротушения тонкораспыленной водой

Object and purpose of research. This paper discusses insufficient flow rate in a standard swirl atomizer of ma-rine water-mist Fi-Fi systems. The purpose of this study was to find the reasons for this insufficient flow rate and the ways to improve it. Materials and methods. This research was a computer-based simulation (in commercial ANSYS CFX package for engineering analysis) based on modern methods of computational fluid dynamics (CFD). Main results. An upgraded swirler for high-flow atomizer preventing cavitation in its inner channels. Conclusion. These results make it possible to design atomizers and sprinklers of marine water-mist Fi-Fi systems with cavitation-free swirler channels.

Effect of Overheating and Incorrect Material Selection on Power Plant Superheater Tube

The present investigation portrays the tube failure in the superheater used in the power plants. The failure occurred after only three months of operation, by longitudinal fish-mouth rupture. The operating pressure of the object boiler is 192 bar while the temperature of its superheater steam is 540 °C. The failed tubes were fabricated from standard Si killed carbon steel. Many longitudinal parallel fine crack-like grooves were detected at the outer surface of the rupture area. Metallurgical examinations revealed that the failed tube remained subjected to overheating for the short-term. According to the analysis of the failed tubes, the temperature reached over 600 °C by insufficient coolant flow or unpredicted operating conditions. The carbon steel emerged as an underperforming material for the applications in superheater tubes, and it is highly recommended to replace the carbon steel by a high-grade Cr-Mo steel.

Hybrid and parallel extracorporeal membrane oxygenation circuits

Hybrid and parallel extracorporeal membrane oxygenation circuits

Combating insolvency and business recovery problems in the oil industry: proposal for improvement in Nigeria's insolvency and bankruptcy legal framework

Insolvency and business recovery laws in Nigeria have not evolved to incorporate reorganisation, reforming insolvent oil firms' operations to boost commercial oil firms' steadiness and economic suitability like other moderately developed countries. In Nigeria, liquidation is understood by many as the panacea to indebtedness. The research evaluates the Nigerian insolvency and business recovery legal regime to sustain indebted oil firms from economic shocks due to the global decline in the oil price to avert imminent business failures due to insufficient cash flows. The aim is to fill the gaps in Nigeria's insolvency and business recovery laws by recommending a model for the sustenance of oil firms and to suggest the reform of the gaps identified in the existing laws and the extant literature on the subject. The paper opted for conceptual legal review, comparative legal and policies analyses of solvency and business recovery legislations in Nigeria, Malaysia, India, South Africa, the United Kingdom and the United States. These nations were designated for this study because their insolvency and business recovery legal regime are business rescued driven, not winding up centred. The study is library research-based to address some of the flaws in Nigeria's insolvency and business recovery laws. The study finds that Nigerian legislation on insolvency is flawed in oil firms' salvage, improvement and rearrangement. It ends that, statutory bodies in the designated case study nations are efficient than those in Nigeria due to the strong political will of their governments in supporting insolvent oil firms for successful financial recovery, to safeguard jobs, to protect creditors and to enhance the wealth of their nations through sound business recovery policies and laws. The study, advocates, remodel of Nigeria's insolvency and business recovery legislations and policies in compliance with the international standards on insolvent oil firms salvaged and creditors focused policies for a robust economy. The study concludes with the recommendation for further study to consider quantitative analysis research methodology to project further scholarship on the subject.

Relationship between Serum YKL-40 Level and Forearm Arterial Patency after Repair

The study aimed to assess the effects of serum YKL-40 level on patency at the repair site in patients who underwent arterial repair at the level of the forearm. The study included 58 subjects, including 29 patients (aged 18-50 years) who had ulnar or radial artery injury secondary to cut injury to wrist between June 2015 and November 2019 and no comorbid disease and 29 age- and sex-matched healthy controls. The vascular patency was assessed using Doppler sonography in patients who underwent arterial repair at the level of the forearm. The patients were defined as flow failure if the blood flow was ≤50%, and sufficient flow if the blood flow was >50% of those in the synonymous artery on the intact extremity. The YKL-40 level differences in the patient and control groups were compared to those in the sufficient and insufficient flow groups. The patients were stratified into 2 groups based on the presence of sufficient flow. The mean YKL level was 11.96 ± 8.87 in the sufficient flow groups, whereas it was 32.22 ± 15.43 in the insufficient flow groups (p= 0.038). Besides, it was found that each unit of increase in the YKL-40 level increased the likelihood of having flow failure by 1.128. Based on our results, it was observed that over-expression of the YKL-40 level has adverse effects on patency following arterial repair.

The impact of insufficient cash flow on payment term and supply chain contracts

ABSTRACT Payment term is an essential part of contract in a supply chain. We consider a supply chain with a retailer who moves first to choose one of three payment terms, e.g. ‘early payment’ (EP), ‘delayed payment’ (DP) and ‘punctual payment’ (PP) and a manufacturer who may have a preference conflict on the payment term with the retailer. Analysing with a sufficient cash flow as a benchmark, strategic impact of insufficient cash flow on payment term and supply chain contracts is investigated to mitigate the conflict. Our study shows that the retailer with cash constraint moves from EP to DP when the initial cash is very small, otherwise holds EP either by borrowing a bank loan with a large wholesale price or using up all initial cash with a small wholesale price. Moreover, a subsidy contract with large wholesale price under the retailer’s cash constraint absolutely mitigates the payment preference conflict, while the revenue-sharing contract with small wholesale price may be effective. Moreover, under the manufacturer’s cash constraint, the retailer is better off under EP, while the manufacturer prefers DP with (without) bank credit related to a small (larger) interest rate when wholesale price is small, then prefers EP as cash flow decreases. Furthermore, the revenue-sharing contract is more effective.

Superior vena cava syndrome during veno-venous extracorporeal membrane oxygenation for COVID-19.

Superior vena cava (SVC) syndrome is typically associated with malignant tumors obstructing the SVC, but as many as 40% of cases have other etiologies. SVC obstruction was previously described during veno-venous extracorporeal membrane oxygenation therapy (VV ECMO) in children. In this report, we describe a woman with adult respiratory distress syndrome resulting from infection with coronavirus-19 who developed SVC syndrome during VV ECMO. A dual-lumen ECMO cannula was inserted in the right internal jugular vein, but insufficient ECMO circuit flow, upper body edema, and signs of hypovolemic shock were observed. This clinical picture resolved when the right internal jugular vein was decannulated in favor of bilateral femoral venous cannulae. Our report demonstrates that timely recognition of clinical signs and symptoms led to the appropriate diagnosis of an uncommon ECMO complication.

Impact of prolonged clamping of the portal vein during liver transplantation in infants with biliary atresia: renewed interest in a long-standing issue.

Various approaches to portal vein (PV) reconstruction have been described; however, there is still scope to improve the safety and efficiency of how PV anastomosis is performed in infants. We analyzed, retrospectively, the predictive factors for PV reanastomosis during living donor liver transplantation (LDLT) in 117 infants (< 1year old) with biliary atresia (BA). Twenty-six infants required PV reanastomosis because of intraoperative PV thrombosis in 21 and insufficient PV flow in 5. Univariate analysis identified multiple previous laparotomies and a prolonged anhepatic phase (AHP) as significant risk factors for repeated PV anastomosis. The AHP cutoff value for identifying patients requiring PV reanastomosis was 134min. Multivariate analysis revealed prolonged AHP > 134min (odds ratio, 15.98; 95% confidence interval, 5.05-50.6; P < 0.001) as an independent risk factor for repeated PV anastomosis. The plasma D-dimer and fibrinogen degradation product concentration just after reperfusion were significantly higher in patients requiring PV reanastomosis (P < 0.001). Patients requiring reanastomosis of the PV had a higher incidence of PV complications after LDLT than those who did not need PV reanastomosis (P = 0.01). Attempting to minimize the AHP is indispensable for successful LDLT in infants with BA.

Optimisation of reservoir operation mode to improve sediment transport capacity of silt-laden rivers

The inverse relationship between water and sediment is hindering the regulation of sediment in silt-laden rivers. Under natural conditions and insufficient water flow, sediment deposits along river channels, resulting in the accumulation of suspended river sediments above the ground level on both sides of the river. Then, during flooding, dam collapse and overflow can easily occur, threatening the life of residents in floodplain. The operation of upstream reservoirs to maximise the sediment transport capacity of downstream rivers into the sea is deemed the best strategy for the management of silt-laden rivers. However, as incoming water and sediment form a dynamic system, optimising the operation mode of reservoirs has become the most severe challenge in the field. This study proposes a method to remodel the water–sediment relationship of natural rivers by optimising the reservoir operation. First, data were collected and analysed to investigate sediment transport in the downstream river channel and the response relationship between erosion–deposition. Then, an empirical equation for calculating the desired incoming sediment was derived, and the threshold for sedimentary transport balance in the lower reach of silt-laden rivers was determined through mathematical modelling. Finally, the reservoir operation mode was optimised within the threshold range to study the discharge process of the reservoir with the highest sediment transport efficiency downstream. The Yellow River in China exhibits the highest sediment concentration worldwide and was used as a case study to verify the practicability of the proposed method. The critical threshold for sediment transport balance in the lower Yellow River was determined to be 250 million tons. The results demonstrate that the proposed method improved the sediment transport capacity of the lower reaches of the Yellow River. Moreover, it reduced the siltation of the XiaoLangDi Reservoir and the lower reaches of the Yellow River. The XiaoLangDi Reservoir can be jointly operated with the Guxian Reservoir, which is under construction and is expected to maintain the bankfull discharge of the lower reaches of the Yellow River at 4000 m3 for a long time. The optimisation process described in this study can be used to improve the management of silt-laden rivers.

Design and development of spiral grooved grinding wheel and their influence on the performance of vertical surface grinding process

In surface grinding process, the insufficient coolant flow causes the accumulation of dislodged abrasives and chips in the grinding interfaces. It leads to poor performance by increased work-surface scratches and reduced material removal rate (MRR). This can be improved by enhancing the coolant flow in the grinding interfaces by creating grooves on grinding wheels surfaces. In this work, a vertical surface grinding process is employed to emphasize the influence of surface integrity of the work-piece with spiral grooved SiC grinding wheel surfaces. The grinding performance (force, power, MRR, wheel wear and G-ratio) and the surface characteristics (avg. roughness, peak-valley height and pitch value) were investigated by varying the process parameters (i.e., depth of cut = 16, 24, 32 and 40 μm and feed rate = 7 and 14 m/min at a constant speed of 1500 rpm). At first, the spiral grooves of four different patterns (Archimedes, Logarithmic, Fermat=t2 and radius=√t) were designed on wheel surfaces and investigated for the stress distribution with the centrifugal force (157 rad/s) by FEM analysis using ANSYS. It reveals that the stress-distribution was larger than the un-grooved wheel surface, irrespective of groove patterns. However, the stress-distribution was found to be lower in Archimedes spiral groove patterns compared to other patterns. Therefore, the case study on Archimedes spiral groove patterns on grinding wheels were performed and compared with the un-grooved wheels.

The Evolution of Financial Fragility: A Quantile Decomposition of Firm Balance Sheets

The post-1980 period has seen an across-the-distribution increase in the cash holdings of U.S. non-financial corporations and falling indebtedness among firms at the bottom 60% of the distribution. These trends are puzzling, given concurrent growth in the share of firms that generate insufficient cash flows to service their financial obligations. We reconcile these trends using quantile decompositions, which show that observed changes across balance sheets reflect firms entering and exiting the corporate sector, rather than the behavior of continuing firms. This finding, which is particularly strong among financially fragile firms, suggest that 'churning', due in particular to changing IPO behavior, is a key mechanism through which financial norms have been disseminated in the last four decades.

Sustainable Floodplains: Linking E-Flows to Floodplain Management, Ecosystems, and Livelihoods in the Sahel of North Africa

Floodplains are particularly important in the semi-arid region of the Sub-Sahelian Africa. In this region, water governance is still being developed, often without adequate information and technical capacity for good, sustainable water resource management. However, water resources are being allocated for use with minimal sustainability considerations. Environmental flows (e-flows) include the quantity and timing of flows or water levels needed to meet the sustainable requirements of freshwater and estuarine ecosystems. Holistic regional scale e-flows linked to floodplain management can make a noticeable contribution to sustainable floodplain management. The Inner Niger Delta (IND) in Mali is an example of a vulnerable, socio-ecologically important floodplain in the Sahel region of North Africa that is being developed with little understanding of sustainability requirements. Although integrally linked to the Upper Niger River catchment, the IND sustains a million and half people within the region and exports food to surrounding areas. The flooding of the Delta is the engine of the socio-economic development as well as its ecological integrity. This paper aims to demonstrate the contribution that holistic regional e-flow assessment using the PROBFLO approach has to achieving floodplain sustainability. This can be achieved through the determining the e-flow requirements to maintain critical requirements of the ecosystems and associated services used by local vulnerable human communities for subsistence and describing the socio-ecological consequences of altered flows. These outcomes can contribute to the management of the IND. In this study, the socio-ecological consequences of altered flows have been evaluated by assessing the risk of alterations in the volume, duration, and timing of flows, to a number of ecological and social endpoints. Based on the risk posed to these endpoints by each scenario of change, an e-flow of 58% (26,685 million cubic meters (MCM) of water annually) was determined that would protect the ecosystem and maintain indicator components at a sustainable level. These e-flows also provide sustainable services to local communities including products for subsistence and limit any abnormal increases in diseases to the vulnerable African communities who live in the basin. Relative risk outputs for the development scenarios result in low-to-high-risk probabilities for most endpoints. The future development scenarios include insufficient flows to maintain sustainability during dry or low-flow periods with an increase in zero flow possibilities. Although unsuitable during the low-flow or dry periods, sufficient water is available through storage in the basin to meet the e-flows if these scenarios were considered for implementation. The IND is more vulnerable to changes in flows compared to the rivers upstream of the IND. The e-flow outcomes and consequences of altered flow scenarios has contributed to the management of vulnerable IND floodplains and the requirements and trade-off considerations to achieve sustainability.

Where is the Planetary Boundary for freshwater being exceeded because of livestock farming?

Livestock production has significant impacts on the environment, including due to the use of water. In this study, we provide a spatially explicit estimation of livestock blue water use, by analyzing feed crop water use and livestock drinking water. For the past four decades, livestock water use has increased from 145 km3/year in 1971 to 270 km3/year in 2012 with an increasing trend of 1.36%/year. The proportion of livestock drinking water use has remained relatively stable at around 10% of total water use attributable to livestock production. Several hotspots of water use, including eastern China, northern India, US high plains, are identified in terms of the long-term averages, while South America and Central Africa show the most rapidly increasing trends. In USA, climate change is found to contribute most to the changes in water use attributable to livestock, while feed cropping intensity and land use change are the dominant driver in China and India, respectively. Though, in total, livestock water use makes a relatively modest contribution to the Planetary Boundary (PB) that has been proposed for anthropogenic water use (4000 km3/year), we argue that this aggregate number is not particularly meaningful, so we identify places where livestock is a major contributor to the unsustainable use of water, in northern India, part of the Middle East, Northern China and Central US. 7% of rivers where excessive water withdrawals mean that there is insufficient residual flow to sustain the aquatic environment (which we take to be the local manifestation of a PB) have been tipped over that boundary because of livestock farming, whilst in a further 34% of rivers, livestock farming on its own exceeds the water PB. Our results provide new and more geographically specific evidence about the impact that the meat industry makes on the PB for water.

Assessing SME Perceptions of Using Green Social Media Marketing

The image of an enterprise in relation to the environment in which it operates is currently of increased importance (Liskova, Cudlinova, Partlova &amp; Petr, 2016, p.64). An enterprise's brand image is a customer's perception of a brand and can help customers assemble information, discriminate brands, create positive feelings, and create a reason to purchase (Huang, Yang &amp; Wang, 2014, p.263). Therefore, enterprises aim to create a strong positive image of their brand which can be generated through marketing programmes. Social media marketing is the application of marketing principles, tools and techniques to social media platforms to differentiate and position the brand better than competitors (Neti, 2011, p.3). Enterprises should therefore use social media to promote and communicate their green initiatives to their stakeholders because of the prominent benefits it offers. Conscious and careful use of social media is the most promising investment for furthering an enterprise's green marketing strategies and by implementing green projects as a CSR initiative SMEs can satisfy their stakeholders (Williams, Page &amp; Petrosky, 2014, p.26). SMEs do not effectively and efficiently market their enterprises due to the lack of funding, insufficient cash flow and the need for technical assistance to market their enterprise (National Small Business Chamber, 2016). Social media is the most popular means of communication in society and provide a good solution as it allows enterprises to interact with their stakeholders through dialogue and engagement to identify and satisfy stakeholder expectations (Bibri, 2008, p.14). The implementation of marketing activities that communicate enterprises' social and environmental initiatives creates added value and enhances financial performance (Bibri, 2008, p.14). If SMEs promote their green initiatives in their marketing communications that are directed at their stakeholders, they could succeed in marketing their business effectively and as a result grow and survive in the long term. However, few SMEs in South Africa are aware that implementing green strategies can improve their profitability and their survival. Keywords: Green marketing; social media marketing; SME's

Experimental Research on Insufficient Water Lubrication of Marine Stern Tube Journal Bearing with Elastic Polymer Bush

Abstract Water-lubricated bearings with polymer bushes are steadily gaining popularity due to their advantages, including environmental friendliness, relatively simple construction and long-term operation. Nevertheless, in practice instances of damage to such bearings occur due to insufficient or absent flow of the lubricating agent. In this study, experimental tests established that elastic polymer bush bearing is capable of operating without excessive wear for a period of at least 60 minutes under conditions of marginal water flow and typical loads for stern tube journal bearings of small ships.

In Vitro Evaluation of Flow Distribution in All-Region Perfusion during the Norwood Operation

Continuous all-region perfusion has the potential to reduce total body ischemia during the Norwood procedure. This technique involves placing cannulas in the innominate artery, descending aorta, and native aortic root, thus providing continuous flow to the whole body at mild hypothermia (32–34°C) during the entire operation. However, the cannulation strategy in this approach must be optimized to achieve adequate flow rates to all vascular beds. To ensure appropriate blood flow rates to three cannulas of different caliber supplied by two inflow pumps, a benchtop evaluation of comparative flow rates through branched cannulas with variable independent perfusion pressures was conducted. Two isolated vertical columns with outlets at 10 mmHg intervals to allow for adjustable perfusion pressures were filled with expired banked packed red blood cells and fresh frozen plasma. The main arterial line was bifurcated with an 8-Fr arterial cannula inserted at the base of one column and a 4-mm (outside diameter [OD]) olive tip cannula inserted at the base of the other column. Flow rates were measured on each branch of the ¼″ arterial lines. Under experimental cardiopulmonary bypass (CPB) perfusion pressures of 30–50 mmHg on the 8-Fr arterial cannula column, the branched olive tip cannula accommodated less than 25% of total flow at total flow rates of 50–700 mL/min. This fraction is insufficient to sustain adequate lower body perfusion. However, the olive tip flow fraction was found to be sufficient for coronary blood flow (5–20 mL/kg/min) when olive tip perfusion pressures close to average neonatal diastolic blood pressures (20–60 mmHg) were tested. For all-region perfusion during the Norwood operation, primary CPB arterial flow should be divided to the head and coronary circulation with an independent pump delivering flow to the descending aorta. This should avoid cerebral over-circulation and insufficient flow to the lower body.

In Vitro Evaluation of Flow Distribution in All-Region Perfusion during the Norwood Operation.

Continuous all-region perfusion has the potential to reduce total body ischemia during the Norwood procedure. This technique involves placing cannulas in the innominate artery, descending aorta, and native aortic root, thus providing continuous flow to the whole body at mild hypothermia (32-34°C) during the entire operation. However, the cannulation strategy in this approach must be optimized to achieve adequate flow rates to all vascular beds. To ensure appropriate blood flow rates to three cannulas of different caliber supplied by two inflow pumps, a benchtop evaluation of comparative flow rates through branched cannulas with variable independent perfusion pressures was conducted. Two isolated vertical columns with outlets at 10 mmHg intervals to allow for adjustable perfusion pressures were filled with expired banked packed red blood cells and fresh frozen plasma. The main arterial line was bifurcated with an 8-Fr arterial cannula inserted at the base of one column and a 4-mm (outside diameter [OD]) olive tip cannula inserted at the base of the other column. Flow rates were measured on each branch of the ¼″ arterial lines. Under experimental cardiopulmonary bypass (CPB) perfusion pressures of 30-50 mmHg on the 8-Fr arterial cannula column, the branched olive tip cannula accommodated less than 25% of total flow at total flow rates of 50-700 mL/min. This fraction is insufficient to sustain adequate lower body perfusion. However, the olive tip flow fraction was found to be sufficient for coronary blood flow (5-20 mL/kg/min) when olive tip perfusion pressures close to average neonatal diastolic blood pressures (20-60 mmHg) were tested. For all-region perfusion during the Norwood operation, primary CPB arterial flow should be divided to the head and coronary circulation with an independent pump delivering flow to the descending aorta. This should avoid cerebral over-circulation and insufficient flow to the lower body.

Flood map production and evaluation of flood risks in situations of insufficient flow data

Flooding, which is the most commonly occurring disaster worldwide, causes the loss of life, injuries and illnesses, psychological trauma and social disruption and damages private and public property and the natural environment. The aim of this study was to complete flood modeling of the Ceviz Stream, which passes through flood-prone Ceviz village, located on a major coastal highway in Ordu Province in the Eastern Black Sea Region of Turkey. More intense rainfall events in the region due to the impact of climate change have led to an increase in flood events in recent years. Due to insufficient flow data in the study area, synthetic unit hydrograph methods were used to estimate flood flow rates. A MIKE FLOOD 1D/2D coupled model was used to describe the overflow zones. The model was calibrated with the data from the major flood event in 2018. Modeling results were assimilated into the ArcGIS environment and different types of flood danger maps were created. Flood risk was calculated with the Dinh, FRMG and FEMA methods, and the results were compared. The results of the study demonstrated that people in Ceviz village and public and private assets are under considerable threat of flooding. Government agencies in Ordu Province can use the generated data and mapping to assist in the development of a holistic suite of policies, plans and actions that minimize the societal and economic impacts of flooding on Ceviz village and coastal highway users.

Dismissals and Temporary Leaves in Romanian Companies in the Context of Low Demand and Cash Flow Problems during the COVID-19 Economic Lockdown

The aim of this study is to describe the relations between low demand, cash flow problems, employee dismissals, and temporary leaves experienced by Romanian companies during the economic lockdown in the first two months of the COVID-19 pandemic outbreak in Romania (16 March–16 May 2020). For this purpose, we conducted a quantitative study using descriptive, correlation, and regression analyses applied to data collected from company decision-makers. Our results show that demand for products/services and cash flow in companies has decreased significantly, the workforce being affected by dismissals and temporary leaves/furloughing. Additionally, the average linear revenue of companies has been decreasing due to insufficient cash flow, higher absenteeism of workers, customers having been affected, and the demand going down. Therefore, employee dismissals, employee temporary leaves (furlough), and dismissal intentions have been positively correlated with insufficient cash flow in companies and an extremely low demand.