Contracting Factor Research Articles

An Advanced Maximum Power Point Tracking Method for Photovoltaic Systems by Using Variable Universe Fuzzy Logic Control Considering Temperature Variability

In this study maximum power point tracking (MPPT) is applied to the photovoltaic (PV) system to harvest the maximum power output. The output power of the PV effect changes according to external solar irradiation and ambient temperature conditions. In the existing MPPT strategies, most of them only take variations in radiation level into account, rarely considering the impact of temperature changes. However, the temperature coefficients (TC) play an important role in the PV system, especially in applications where ambient temperature changes are relatively large. In this paper, an MPPT method is presented for a PV system that considers the temperature change by using variable universe fuzzy logic control (VUFLC). By considering the ambient temperature change in PV modules, the proposed control method can regulate the contraction and expansion factor of VUFLC, which eliminates the influence of temperature variability and improves the performance of MPPT, therefore achieving fast and accurate tracking control. The proposed method was evaluated for a PV module under different ambient conditions and its control performance is compared with other MPPT strategies by simulation and experimental results.

Implementation of Leasing Contract in Non-Banking Finance Institutions

The purpose of this article is to analyze the legal relationship of a Leasing Business financing contract of three legitimate parties and bind between supplier, lessor and lesse. The research methodology is classified as an applied normative-empirical legal research that examines the implementation of positive legal provisions and factual contracts on each lease contract. The type of research is descriptive, which describes the legal events in the form of leasing of business procurement of goods to run the company and analyzed qualitatively.The results refer to Dipo Star Finance companies in Bandar Lampung, Indonesia, concluded that the details of the rights and obligations of the parties were not balanced. The lessor's obligations are limited by a fairly strict exoneration clause. The lessee is responsible for default by the settlement of paying capital goods rent along with late penalties, or withdrawal of capital goods by the lessor. Goodwill of the parties is a supporting factor in the lease contract while the inhibiting factor is the failure to run a business. In order not to burden the lessee, the lessor should be able to set a contract standard containing equal rights and obligations and the parties can enter into a joint agreement in an additional clause that is not separate from the lease contract.

Theoretical framework of optimal contracts (Nobel Prize in Economics 2016 awarded to Oliver Hart and Bengt Holmström)

The article considers Oliver Hart and Bengt Holmström’s contributions to the development of contract theory. The contributions are represented by studies on the nature of optimal contract in view of motivation of contract agents and factors that affect their motivation. A particular attention is placed on the practical utility of the research done by Nobel Laureates in Economic Sciences 2016 that have fostered further studies on the theory of the firm, corporate finance, management, labour economics and the public sector, political science and law. The new theoretical tools created by O. Hart and B. Holmström serve for analysis of financial terms of contracts and for the distribution of supervisiory rights, property rights and decision-making rights. It is emphasized that O. Hart and B. Holmström’s contributions to the field of contract theory present formal treatment of motivation issues, moral hazard and incomplete contracts. The role of contracts in managing future interactions and ensuring conditions for establishing high-quality institutions is recognized. It is pointed out that the contract theory reveals working mechanisms of institutions, and presents potential hazard that may arise when new contracts are being drafted. Particular attention is paid to positioning of the contract theory within the theory of economic organization and the economic theory of information that is aimed at developing models with asymmetric information and taking into account non-observable actions. Real situations, game models and contract structure with the distinction between complete and incomplete contracts are examined (based on the informativeness principle). The performance of multi-task model and career-growth model in the contract theory is outlined. The paper analyzes the impact of the contract theory on changes in approaches to analyzing corporate relationships, which were previously based on the trade-off theory that includes balancing between the reduction of tax payments and corporate debt servicing.

Factors influencing performance by contracted non-state providers implementing a basic package of health services in Afghanistan

BackgroundIn 2002 Afghanistan’s Ministry of Public Health (MoPH) and its development partners initiated a new paradigm for the health sector by electing to Contract-Out (CO) the Basic Package of Health Services (BPHS) to non-state providers (NSPs). This model is generally regarded as successful, but literature is scarce that examines the motivations underlying implementation and factors influencing program success. This paper uses relevant theories and qualitative data to describe how and why contracting out delivery of primary health care services to NSPs has been effective.The main aim of this study was to assess the contextual, institutional, and contractual factors that influenced the performance of NSPs delivering the BPHS in Afghanistan.MethodsThe qualitative study design involved individual in-depth interviews and focus group discussions conducted in six provinces of Afghanistan, as well as a desk review. The framework for assessing key factors of the contracting mechanism proposed by Liu et al. was utilized in the design, data collection and data analysis.ResultsWhile some contextual factors facilitated the CO (e.g. MoPH leadership, NSP innovation and community participation), harsh geography, political interference and insecurity in some provinces had negative effects. Contractual factors, such as effective input and output management, guided health service delivery. Institutional factors were important; management capacity of contracted NSPs affects their ability to deliver outcomes. Effective human resources and pharmaceutical management were notable elements that contributed to the successful delivery of the BPHS. The contextual, contractual and institutional factors interacted with each other.ConclusionThree sets of factors influenced the implementation of the BPHS: contextual, contractual and institutional. The MoPH should consider all of these factors when contracting out the BPHS and other functions to NSPs. Other fragile states and countries emerging from a period of conflict could learn from Afghanistan’s example in contracting out primary health care services, keeping in mind that generic or universal contracting policies might not work in all geographical areas within a country or between countries.

Contracting-out urban primary health care in Bangladesh: a qualitative exploration of implementation processes and experience

BackgroundContracting-out (CO) to non-state providers is used widely to increase access to health care, but it entails many implementation challenges. Using Bangladesh’s two decades of experience with contracting out Urban Primary Health Care (UPHC), this paper identifies contextual, contractual, and actor-related factors that require consideration when implementing CO in Low- and Middle- Income Countries.MethodsThis qualitative case-study is based on 42 in-depth interviews with past and present stakeholders working with the government and the UPHC project, as well as a desk review of key project documents. The Health Policy Triangle framework is utilized to differentiate among multiple intersecting contextual, contractual and actor-related factors that characterize and influence complex implementation processes.ResultsIn Bangladesh, the contextual factors, both intrinsic and extrinsic to the health system, deeply impacted the CO process. These included competition with other health projects, public sector reforms, and the broader national level political and bureaucratic environment. Providing free services to the poor and a target to recover cost were two contradictory conditions set out in the contract and were difficult for providers to achieve. In relation to actors, the choice of the executing body led to complications, functionally disempowering local government institutions (cities and municipalities) from managing CO processes, and discouraging integration of CO arrangements into the broader national health system. Politics and power dynamics undermined the ethical selection of project areas. Ultimately, these and other factors weakened the project’s ability to achieve one of its original objectives: to decentralize management responsibilities and develop municipal capacity in managing contracts.ConclusionsThis study calls attention to factors that need to be addressed to successfully implement CO projects, both in Bangladesh and similar countries. Country ownership is crucial for adapting and integrating CO in national health systems. Concurrent processes must be ensured to develop local CO capacity. CO modalities must be adaptable and responsive to changing context, while operating within an agreed-upon and appropriate legal framework with a strong ethical foundation.

Saturation and Reliable Hierarchical a Posteriori Morley Finite Element Error Control

This paper proves the saturation assumption for the nonconforming Morley finite element discretization of the biharmonic equation. This asserts that the error of the Morley approximation under uniform refinement is strictly reduced by a contraction factor smaller than one up to explicit higher-order data approximation terms. The refinement has at least to bisect any edge such as red refinement or 3-bisections on any triangle. This justifies a hierarchical error estimator for the Morley finite element method, which simply compares the discrete solutions of one mesh and its red-refinement. The related adaptive mesh-refining strategy performs optimally in numerical experiments. A remark for Crouzeix-Raviart nonconforming finite element error control is included.

Manipulator multi-objective motion optimization control for high voltage power cable mobile operation robot

In respond to the problem of the manipulator point to point motion planning of power cable mobile operation robot, a trajectory planning method based on joint motion time standardization combined with time contraction factor is proposed in this paper, the joint motion time is selected as an evaluation parameter of joint trajectory performance, and corresponding, the mapping relationship between trajectory performance and different joint motion time is also studied. Based on the research result and combined with the robot kinetics model, a mixing constraint control method of joint position, velocity and acceleration is proposed so as to realize the continuous, smooth, stable and non-collision obstacle avoidance motion optimization under the condition of joint global state constraints during manipulator operation motion. Compared with the traditional algorithm, the improved algorithm has achieved excellent trajectory performance under the premise of ensuring the safety manipulator motion, and this method can also avoid the occurrence of joint motion overshoot, which not only improve the efficiency of joint space motion but also reduce the energy consumption. Finally, the feasibility and effectiveness of the proposed algorithm are verified through simulation experiments and the engineering practicality of the proposed algorithm is verified by the field operation experiments.

Decreased contraction induced by endothelium-derived contracting factor in prolonged treatment of rat renal artery with endoplasmic reticulum stress inducer

Recent evidence suggests that endoplasmic reticulum (ER) stress is involved in the regulation of various physiological functions, including those of the vascular system. However, the relationship between ER stress and vascular function is poorly understood. The endothelial cells control the vascular tone by releasing endothelium-derived relaxing factors and contracting factors (EDCFs). We hypothesized that tunicamycin, an inducer of ER stress, modifies endothelium-dependent contraction and prostaglandins (PGs), a major class of EDCFs, induced contractions in the rat renal artery in rats. An organ-culture technique was used to purely investigate the effects of ER stress on the vascular tissue. We observed that tunicamycin treatment (20μg/mL for 23 ± 1h) did not affect acetylcholine (ACh)-induced relaxation and decreased EDCF-mediated contractions under nitric oxide synthase (NOS) inhibition induced by ACh, ATP, or A23187 (a calcium ionophore) in the renal arteries. Under NOS inhibition, U46619 (a thromboxane A2 mimetic)- and beraprost (a prostacyclin analog)-induced contractions were also decreased in the renal arteries of the tunicamycin-treated group (vs. vehicle), while PGE2- and PGF2α-induced contractions were similar between the groups. Tunicamycin treatment slightly enhanced the contractions induced by phenylephrine, an α1 adrenoceptor ligand. Isotonic high-K+-induced contractions were similar between the vehicle- and tunicamycin-treated groups. Another ER stress inducer, thapsigargin (4μmol/L for 23 ± 1h), also caused substantial reduction of ACh-induced EDCF-mediated contraction (vs. vehicle-treated group). In the cultured renal arteries, tunicamycin and thapsigargin increased the expression of binding immunoglobulin protein (BiP), an ER stress marker. In conclusion, ER stress induction directly affects renal arterial function, especially in reducing EDCF-mediated contractions.

Investigation of the Klinkenberg effect in a micro/nanoporous medium by direct simulation Monte Carlo method

We define effective pore size as a function of the porosity, the tortuosity, the contraction factor, and the intrinsic permeability of the porous medium. The Klinkenberg effect in different porous structures is found to be fully described by the Knudsen number characterized by this pore size.

Buyback and stockout penalty newsvendor model based on reference point prospect theory

Expected utility theory is as main analysis of newsvendor problem, which has generally accepted as a normative model of rational choice. However, various independent experimental studies have shown the actual order quantity of decision maker deviates from the theoretical optimal order quantity. In the framework of prospect theory, the newsvendor experimental results are interpreted by compromise decision value as a reference point. And we join the buyback contract and stockout penalty factors and calculate respectively newsvendor optimal order quantity in three situations respectively. And then prove the monotonicity the optimal order quantity with loss aversion coefficient, buyback price and stock-out penalties.

Analysis method of competitive advantage of new industrial innovation alliance based on contraction factor particle swarm optimization (PSO)

To improve effectiveness of competitive advantage analysis algorithm of emerging industry innovation union, a kind of competitive advantage analysis method of emerging industry innovation union based on constriction factor particle swarm optimization (PSO) is proposed. Firstly, competitive advantage evaluation model of emerging industry innovation union is constructed aimed at uncertain influence factor existing in evaluation to strategic emerging industry; secondly, particle swarm optimization is introduced, and to avoid premature convergence problem existing in particle swarm optimization and realize rapid convergence of particle to global optimal solution, constriction factor and two operators, i.e. “attraction” and “diffusion”, are introduced in this paper so that diversity of particle swarm is kept and better convergence rate is possessed. Finally, through empirical analysis to strategic emerging industry evaluation of an area, feasibility and rationality of the method are verified.

ADAPTING TO DEMOCRACY: IDENTITY AND THE POLITICAL DEVELOPMENT OF NORTH KOREAN DEFECTORS

AbstractDefection from North Korea to South Korea has increased dramatically, but little is known of its political consequences. Do North Korean defectors successfully adopt democratic norms, and if so, what factors aid this process? Through a novel survey of defectors, I find that national identification plays a significant role in motivating their fledgling sense of democratic obligation. Greater feelings of national unity with South Koreans lead to a stronger duty to vote and otherwise contribute to the democratic state. This effect is more powerful than that of conventional contractual factors, on which most state resettlement policies are based, and is surprising given that defectors’ nationalist socialization mostly took place under the authoritarian North. The findings suggest the need to reconsider integration approaches toward North Korean defectors and similarly placed refugees elsewhere.

Managerial Equity Incentives, Controlling Shareholder Characteristics and the Choice of Credit Contracts

In the relatively concentrated ownership structure, the design and implementation of managerial equity incentive plan are easily affected by controlling shareholders. The difference in the governance effect of controlling shareholders will have different effects on corporate financing demand and capability under the managerial equity incentives. The current research on equity incentives and corporate credit contract selection revolves around management agent issues, but pays little attention to the difference in the governance effect of controlling shareholders. Based on the signal transmission effect, the controlling shareholders influence the credit decisions of the banks as the credit suppliers, thus affecting corporate credit financing ability under the equity incentives. Therefore, this paper incorporates the controlling shareholders, executives and banks into the same analytical framework, to study the implementation of equity incentives on the choice of credit contracts based on the regulatory role of the controlling shareholders. Using the sample composed of listed corporations implementing the managerial equity incentives from 2009 to 2015, we empirically examine the effect of the game among controlling shareholders, executives, and banks under different managerial equity incentives on the choice of credit contracts based on behavior guide and signaling effects of managerial equity incentives under the moderation role of three types of controlling shareholders, namely state-owned controlling shareholders, non-state-owned controlling shareholders with the separation of cash flow right and control right, and non-state-owned controlling shareholders with the matching of cash flow right and control right. Using PSM method & DID model and after controlling endogenous influences of scale, maturity and costs as three major elements of credit contracts and other factors influencing the choice of credit contract factors, we get the empirical conclusions. Firstly, equity incentives in the state-owned companies have become the tool for executives to seek welfare and aggravate the managerial agency problem. However, the existence of bank soft budget constraints formed from government intervention can lead to more credit funds preference（especially long-term credit funds）. Secondly, the moderation role of ultimate controlling shareholders in equity incentives in non-state-owned enterprises is closely related with the separation of cash flow right and control right. When cash flow right and control right are matched, managerial equity incentives could promote the expectancy of internal management level and thereby non-state-owned enterprises obtain relaxed credit contracts. However, the equity incentives with high separation of cash flow right and control right for ultimate controlling shareholders induce the banks to reduce the expectancy of internal governance level of debtor companies and lead to more rigorous credit contracts. This paper expands the research of governance effect of managerial equity incentives, and has important reference value for improving corporate governance mechanism and effective implementation of managerial equity incentive plan. It concludes that a state-owned enterprise can deepen the reform of government decentralization and equity incentive system to provide decision-making and optimization of enlightenment for current financial institutions in the credit supply-side reform provided the screening and control of credit risk, equity incentive companies; on the other hand, it has the reference value for how the micro enterprises transfer the signal of the increase in internal corporate governance to financial institutions by equity incentives and then realize the access to relaxed credit contracts.

Accelerated Particle Swarm Optimization to Solve Large-Scale Network Plan Optimization of Resource-Leveling with a Fixed Duration

Large-scale network plan optimization of resource-leveling with a fixed duration is challenging in project management. Particle swarm optimization (PSO) has provided an effective way to solve this problem in recent years. Although the previous algorithms have provided a way to accelerate the optimization of large-scale network plan by optimizing the initial particle swarm, how to more effectively accelerate the optimization of large-scale network plan with PSO is still an issue worth exploring. The main aim of this study was to develop an accelerated particle swarm optimization (APSO) for the large-scale network plan optimization of resource-leveling with a fixed duration. By adjusting the acceleration factor, the large-scale network plan optimization of resource-leveling with a fixed duration yielded a better result in this study than previously reported. Computational results demonstrated that, for the same large-scale network plan, the proposed algorithm improved the leveling criterion by 24% compared with previous solutions. APSO proposed in this study was similar in form to, but different from, particle swarm optimization with contraction factor (PSOCF). PSOCF did not have as good adaptability as APSO for network plan optimization. Accelerated convergence particle swarm optimization (ACPSO) is similar in form to the APSO proposed in this study, but its irrationality was pointed out in this study by analyzing the iterative matrix convergence.

The Necessity of Active Muscle Metabolism for Healthy Aging: Muscular Activity Throughout the Entire Day.

There is more need for "a movement-movement" than ever before. The percentage of seniors in our population is rising exponentially. Sedentary lifestyles throughout the lifespan have become the norm, including inactive youth and a sedentary workforce. Preventable chronic diseases caused by sedentary living have both lowered the quality of life for those directly affected or their families, and have created an unsustainable economic dilemma. In this article, we explain that whether it is a sedentary student, worker, or retiree, the most neglected but essential facts are as follows. By far, the most potent and rapid way to raise the rate of healthy metabolic and cardiovascular processes is through the immediate benefits of muscle contractions. Working muscle demands more energy and fuel than any other tissue in the body, but during inactivity the metabolic rate of muscle is relatively low. Depending on the type of contraction, muscle type, and other factors, the local fuel requirements within the working muscle can help to manage metabolic risks through a variety of processes, such as blood glucose utilization, uptake of unhealthy blood triglycerides, and increased blood flow. Given the large amount of time that people spend inactive each day, there is an enormous opportunity to raise the bar in optimizing health throughout the entire lifespan. Developed correctly, safe and low effort muscular activity can be performed for relatively long periods of time each day by the elderly and all segments of the population to optimize health and well being during aging.

Acute stimulation of a smooth muscle constrictor by oestradiol-17β via GPER1 in bovine oviducts.

Oviducts play roles in reproductive processes, including gametes transport, fertilization and early embryo development. Oviductal transport is controlled by various factors such as endothelins (EDNs) and nitric oxide (NO), smooth muscle contracting and relaxing factor, respectively. EDNs and NO production depend on an ovarian steroid hormone, oestradiol-17β (E2) and E2 quickly exerts their biological functions through G protein-coupled oestrogen receptor 1 (GPER1), which mediates rapid intracellular signalling. Because follicular fluid which contains a high concentration of E2 enters the oviduct, we hypothesized that E2 in the follicular fluid participates via GPER1 in producing EDNs and NO. To test this hypothesis, we investigated 1) the expression and localization of GPER1 in bovine oviductal tissues and 2) rapid effects of E2 via GPER1 on EDN1, EDN2 and inducible NO synthase (iNOS) expression in cultured bovine oviductal isthmic epithelial cells. GPER1 was observed in the oviductal epithelium, stroma and smooth muscle, and its expression was highest in the isthmus. Short-term treatments (≤1hr) of E2 increased EDN2 mRNA expression in the isthmic epithelial cells, although E2 did not affect EDN1 and iNOS mRNA expressions. Results of GPER1-selective agonist G-1 and GPER1-selective antagonist G-15 treatments revealed acute stimulation by E2, which is mediated via GPER1. The overall findings suggested that E2 in follicular fluid rapidly stimulates EDN2 expression via GPER1 in the isthmic epithelial cells. Follicular fluid may play a role in retention of the ovulated oocyte in the end of ampulla by contracting the isthmus for successful fertilization.

TRPV4 (Transient Receptor Potential Vanilloid 4) Mediates Endothelium-Dependent Contractions in the Aortas of Hypertensive Mice.

The role of TRPV4 (transient receptor potential vanilloid 4) in regulating vascular contraction in hypertensive mice is poorly established. We tested the hypothesis that TRPV4 regulates endothelium-dependent contractions in aortas from hypertensive mice through the activation of cytosolic cPLA2 (phospholipase A2) and COX2 (cyclooxygenase 2) and identified the possible endothelium-derived contracting factor generated by COX2. Using myography, we demonstrated that GSK1016790A (a TRPV4 agonist) and acetylcholine (ACh) trigger endothelium-dependent contractions in aortas from hypertensive mice, and the contractions were abolished with TRPV4 deletion. PLA2 assay and Western blotting showed that cPLA2 activity was higher in salt-induced hypertension and HC067047 or a Ca2+ chelator inhibited cPLA2 activity. Contractions induced by TRPV4 and ACh were inhibited by the cPLA2 inhibitor or removal of extracellular Ca2+ COX2 expression was enhanced in the endothelium from hypertensive mice and contractions induced by TRPV4 or ACh were inhibited by the COX2 inhibitor. Enzyme immunoassay showed that the release of prostaglandin F2α (PGF2α) was increased in hypertensive mice. GSK1016790A or ACh triggered the release of PGF2α and this was inhibited by HC067047, the cPLA2 inhibitor, and COX2 inhibitor. GSK1016790A, ACh, and PGF2α induced contractions were significantly reduced by S18886 in salt-induced hypertensive mice. The present study demonstrates that PGF2α generated by COX2 in the endothelium is the most likely endothelium-derived contracting factor underlying endothelium-dependent, TRPV4-mediated contraction in hypertensive mice. This contraction involved increased intracellular Ca2+ concentrations and cPLA2 activity. These results suggested an important role of TRPV4 in endothelium-dependent contraction in mice during hypertension.

A view from the vendor’s side: factors that determine satisfaction

PurposeWith the growth in outsourcing it is imperative to understand the vendor’s satisfaction with IT outsourcing relationships since contractual and relationship factors affect the ability of vendors and clients to work together over time. A recent study demonstrated that relational factors such as trust and information exchange dominated in their ability to explain client satisfaction when compared to contractual factors. The purpose of this paper is to further examine how the relational factors work together to lead to vendor satisfaction in an outsourcing relationship.Design/methodology/approachA survey was developed and pre-tested with vendors in India and client firms in the USA that used international IT vendors. Using data collected from 214 vendor firms in the Indian subcontinent the paper examines the main effect of two client focused variables, namely, competence-based trust and client dependence on vendor satisfaction; it also explores whether social control moderate the main effect relationships.FindingsThe findings indicate that client dependence and competence-based trust were significant direct predictors of vendor satisfaction. Social control or the ability to resolve conflicts positively moderated the effect client dependence on vendor satisfaction. But it did not impact the effect of competence-based trust on vendor satisfaction.Research limitations/implicationsThe authors identify three limitations: a dyadic analysis using both the client and the vendor perspective would have provided a richer understanding of the relationship; since the data were collected on a cross-sectional basis, it is hard to make predictive assessments; and a limited response rate.Practical implicationsThese findings help us understand the factors that impact vendor satisfaction in an outsourcing relationship and this is one of the keys to maintaining a long-term relationship between transacting parties.Originality/valuePrevious studies have explored the relational aspects of a vendor-client interaction from the client’s point of view and, here, the authors take the vendor’s perspective, which is increasingly important due to the increasing complexity of work outsourced. Besides exploring the direct effect competence-based trust and client dependence on vendor satisfaction, the authors also analyze the role of social control as a moderator.

The role of health information technology in advancing care management and coordination in accountable care organizations.

To be successful, accountable care organizations (ACOs) must effectively manage patient care. Health information technology (HIT) can support care delivery by providing various degrees of coordination. Few studies have examined the role of HIT functionalities or the role of different levels of coordination enabled by HIT on care management processes. We examine HIT functionalities in ACOs, categorized by the level of coordination they enable in terms of information and work flow, to determine which specific HIT functionalities and levels of coordination are most strongly associated with care management processes. Retrospective cross-sectional analysis was done using 2012 data from the National Survey of Accountable Care Organizations. HIT functionalities are categorized into coordination levels: information capture, the lowest level, which coordinates through standardization; information provision, which supports unidirectional activities; and information exchange, which reflects the highest level of coordination allowing for bidirectional exchange. The Care Management Process index (CMP index) includes 13 questions about the extent to which care is planned, monitored, and supported by providers and patients. Multiple regressions adjusting for organizational and ACO contractual factors are used to assess relationships between HIT functionalities and the CMP index. HIT functionality coordinating the most complex interdependences (information exchange) was associated with a 0.41 standard deviation change in the CMP index (β = .41, p < .001), but the associations for information capture (β = -.01, p = .97) and information provision (β = .15, p = .48) functionalities were not significant. The current study has shed some light on the relationship between HIT and care management processes by specifying the coordination roles that HIT may play and, in particular, the importance of information exchange functionalities. Although these represent early findings, further research can help policy makers and clinical leaders understand how to prioritize HIT development given resource constraints.

The Vibrations Study of DAMMAR Based Composite Bars Reinforced with Natural Fibers by Using a New Euler - Bernoulli Theory

In the paper it is presented a new Euler - Bernoulli theory based on an assymetrical distribution of strains towards the median plane, the area subjected to compression has a transversal stretching, while the area subjected to tensile has a transversal contraction. This theory takes into account the transversal contraction factors and consequently the eigenpulsations of bars vibrations with rectangular section depend on the ratio between the bars width and thickness. This theory is experimentally verified for Dammar based composite bars reinforced with cotton, flax, silk and hemp fibers. For the considered bars, we have experimentally determined the eigen frequencies and the damping factor values.