Insignificant Barriers Research Articles

Analysis of the Attitudes of Central European Small- and Medium-Sized Enterprises towards Adaptation to the Low-Carbon Economy and Its Implementation Barriers

As developed regions explore avenues to enhance their industries in order to become climate-neutral, numerous studies have identified distinct factors that may hinder the shift towards a low-carbon economy. The objective of our research was to pinpoint key barriers to adaptation to a low-carbon economy among small- and medium-sized enterprises (SMEs) of Central Europe from the viewpoint of the company’s structure. The aim was to examine whether attitudes towards barriers to adaptation to a low-carbon economy represent a key factor that prevents the faster and more effective uptake of such adaptations by SMEs. Both the industrial and service sectors were considered. A quantitative data collection method, CATI, was employed. Using our methodology, we applied a non-parametric testing procedure, specifically, the Kruskal–Wallis test, to compare more than two independent samples, together with the Mann–Whitney U test. Through this analysis, it was found that companies regard the uncertainty of return on investment and its payback period as the most serious barrier to adaption to a low-carbon economy. Meanwhile, the lack of cooperation with research institutions and universities is perceived as the least important barrier. Companies are critical of existing regulations for adaptation to the low-carbon economy, which do not provide incentives for companies, though sole traders consider this an insignificant barrier. The shift towards a low-carbon economy is one of the greatest challenges of the 21st century. Understanding the initial motivational variables can significantly contribute to the process of transition towards the use of renewable energy sources by companies, regardless of their size or sector.

Unveiling the Role of Charge Transfer in Enhanced Electrochemical Nitrogen Fixation at Single-Atom Catalysts on BX Sheets (X = As, P, Sb).

To tune single-atom catalysts (SACs) for effective nitrogen reduction reaction (NRR), we investigate various transition metals implanted on boron-arsenide (BAs), boron-phosphide (BP), and boron-antimony (BSb) using density functional theory (DFT). Interestingly, W-BAs shows high catalytic activity and excellent selectivity with an insignificant barrier of only 0.05 eV along the distal pathway and a surmountable kinetic barrier of 0.34 eV. The W-BSb and Mo-BSb exhibit high performances with limiting potentials of -0.19 and -0.34 V. The Bader-charge descriptor reveals that the charge transfers from substrate to *NNH in the first protonation step and from *NH3 to substrate in the last protonation step, circumventing a big hurdle in NRR by achieving negative free energy change of *NH2 to *NH3. Furthermore, machine learning (ML) descriptors are introduced to reduce computational cost. Our rational design meets the three critical prerequisites of chemisorbing N2 molecules, stabilizing *NNH, and destabilizing *NH2 adsorbates for high-efficiency NRR.

Unraveling the permeation of reactive species across nitrated membranes by computer simulations.

Reactive oxygen and nitrogen species (RONS) are involved in many biochemical processes, including nitro-oxidative stress that causes cancer cell death, observed in cancer therapies such as photodynamic therapy and cold atmospheric plasma. However, their mechanisms of action and selectivity still remain elusive due to the complexity of biological cells. For example, it is not well known how RONS generated by cancer therapies permeate the cell membrane to cause nitro-oxidative damage. There are many studies dedicated to the permeation of RONS across native and oxidized membranes, but not across nitrated membranes, another lipid product also generated during nitro-oxidative stress. Herein, we performed molecular dynamics (MD) simulations to calculate the free energy barrier of RONS permeation across nitrated membranes. Our results show that hydrophilic RONS, such as hydroperoxyl radical (HO2) and peroxynitrous acid (ONOOH), have relatively low barriers compared to hydrogen peroxide (H2O2) and hydroxyl radical (HO), and are more prone to permeate the membrane than for the native or peroxidized membranes, and similar to aldehyde-oxidized membranes. Hydrophobic RONS like molecular oxygen (O2), nitrogen dioxide (NO2) and nitric oxide (NO) even have insignificant barriers for permeation. Compared to native and peroxidized membranes, nitrated membranes are more permeable, suggesting that we must not only consider oxidized membranes during nitro-oxidative stress, but also nitrated membranes, and their role in cancer therapies.

Assessment of Barriers to Small and Medium Enterprises from Engaging in Export Business in Case of Mekelle City, Ethiopia

The overriding purpose of this study was to assess the barriers that hinder small and medium enterprises (SMEs) from engaging in export business in the case Mekelle city Ethiopia. The study employed both descriptive and explanatory research design. 252 SMEs were taken as total population, from these 155 sample respondents were selected from three types of business by using a proportionate stratified random sampling technique. To collect relevant data, this study used both questionnaires and interviews; then, data collected through questionnaires analyzed using descriptive and inferential statistics and presented through tables and figures. Hypotheses were developed and tested. To examine the relationship between the dependent and independent variables multiple regression employed and analyzed with the help of SPSS version 16. Multiple regression results revealed that the independent variables i.e. financial, informational, marketing, functional, procedural, and governmental barriers explain 50.3% of the dependent variable i.e. export business engagement. Moreover, the independent variables such as financial, marketing, functional, procedural, and governmental barriers founded to be significant barriers impeding SMEs from engaging in export business. However informational related barrier was founded to be an insignificant barrier. Finally, to overcome the identified barriers, the researcher recommended both the runners of SMEs and the government bodies. Greater efforts is required from runners to get adequate finance, government bodies should provide assistance to SMEs through continuously monitoring the environment, strengthening lending institutions, and formulating appropriate policies that encourage small business get involved in export business. Keywords: external barriers, export business, internal barriers, Mekelle, SMEs DOI: 10.7176/JESD/11-18-02 Publication date: September 30 th 2020

Perceived Barriers and Trends in HPV Vaccination via Patient Survey Responses at Kalamazoo, Michigan's Federally-Qualified Health Center.

Human Papillomavirus (HPV) is the most common sexually transmitted infection (STI) in the United States. Despite numerous studies proving the safety and efficacy of the HPV vaccine, immunization rates remain low, especially among underserved populations. To identify factors contributing to low HPV vaccination rates, patients at a federally qualified health center in Kalamazoo MI were surveyed. Surveys were administered during routine patient visits to determine self-reported vaccination status and vaccination barriers. A total of 98 vaccine-eligible (males/females, ages 9-26years old) patients/guardians completed the survey. In all, 46% of respondents completed the multi-dose vaccination course, and 56% of those identified as female. White patients reported higher vaccination rates (50%) than patients of color (45%). Of those vaccinated, the most common reason was "physician recommendation" (39%). Those not fully vaccinated most commonly reported being "too young" (39%). Importantly, individuals who had begun, but not completed, the vaccination course reported that their provider had not spoken to them about future vaccines in the series (74%). This study revealed disparities in vaccination rates between the sexes and racial groups, and emphasized the influential role of physician's recommendation on vaccination. Interestingly, other frequently cited barriers to vaccination-an association with sex, personal/religious beliefs, efficacy-proved to be insignificant barriers for this population. Instead, age-related misunderstandings and lack of consistent physician communication about vaccination provided significant barriers. Based on our results, education and reminders about the HPV vaccine by providers is a significant tool to maximize vaccination coverage.

Discrete Existence of Singlet Nitrenium Ions Revisited: Computational Studies of Non-Aryl Nitrenium Ions and Their Rearrangements.

Nitrenium ion species are examined using computational methods (DFT, MP2, coupled-cluster, and a composite method, CBS-APNO) with a particular emphasis on nonaromatic species (i.e., those lacking an aromatic or heteroaromatic ring in direct conjugation with the formal nitrenium ion center.) The substitution of the N+ center with alkyl, alkoxy, vinyl, acyl, and sulfonyl, among others, was evaluated. For these species, three properties are considered. (1) The stability of the nitrenium ions to unimolecular isomerizations such as 1,2 alkyl or H shifts; to the extent that the singlet states could be characterized as discrete minima on the potential energy surface (PES), (2) the effect of the substituents on singlet–triplet energy splitting as well as (3) the relative stabilities of the nitrenium ions as defined by N-hydration enthalpies (RR′N+ + H2O → RR′NOH2+). Nearly all simple alkyl and di-alkyl nitrenium ion singlet states are predicted to rearrange without detectable barriers, largely through 1,2 H or alkyl shifts. Methyl and N,N-dimethylnitrenium ion singlet states could be characterized as formal minima on the PES. However, these species show small or insignificant barriers to isomerization. Disubstituted nitrenium ions that include an alkyl group and a conjugating substituent such as alkoxyl, vinyl, or phenyl show meaningful barriers to isomerization and are thus predicted to possess nontrivial lifetimes in solution. Alkyl groups substantially stabilize the singlet state relative to the situation in the parent nitrenium ion NH2+ to the point where the two states are nearly degenerate. Other groups that interact with the nitrenium ion center decrease the ΔEst in the order formoyl < vinyl < phenyl < alkoxy ∼ sulfonyl < cyclopropyl ∼ cyclobutyl. The latter two substituents interact strongly with the (singlet) nitrenium ion center through the formation of a nonclassical bonding reminiscent of the bisected cyclopropylcarbinyl ion case for carbocations. When singlet-state stability is evaluated in the context of N-hydration enthalpies, it is found that the ordering is acyl < vinyl < alkoxyl < phenyl < cyclopropyl and cyclobutyl.

Increasing zoo’s conservation potential through understanding barriers to holding globally threatened amphibians

The global amphibian crisis and current un-mitigatable threats make ex situ programmes a crucial complementary action for the conservation of many amphibians. Zoos and aquariums are some of the most important and influential groups of institutions to undertake this yet the proportion of globally threatened amphibians in zoos is just 23.9% compared to over 40% in the wild. To identify key barriers to holding globally threatened amphibian species in ex situ collections, as well as potential strategies to mitigate such barriers, we surveyed amphibian curators across 107 institutions worldwide. A lack of resources (including budget, staffing and space) was perceived as the most significant barrier (87% of respondents) and the barrier most frequently identified (119 responses), followed by disease/biosecurity concerns (31 responses), and a lack of staff expertise/knowledge (30 responses). Difficulty displaying amphibians due to cryptic behaviour or colouration (65% or respondents) and difficulty attracting visitor interest (60% of respondents) were seen as insignificant barriers. Nine key priority action areas were identified, with increasing interest from zoo leadership and budget allocation identified as the most important (49% of suggested solutions). Increasing visitor interest in amphibians to encourage increased investment and engaging with range country facilities were highlighted as two ways to address barriers. Careful collection planning considering both the need and suitability of a species for captive breeding is also key, whilst critically assessing the role each species will play in a collection will enable a better assessment of the collection’s conservation value rather than using global threat status alone.

Harry Truman and the Struggle for Racial Justice. By RobertShogan. Lawrence: University Press of Kansas, 2013. 248 pp.

Harry Truman and the Struggle for Racial Justice. By Robert Shogan. Lawrence: University Press of Kansas, 2013. 248 pp. Robert Shogan gives us a readable, well-researched, and inviting account of Truman's role in civil rights. Shogan peppers his text with brief, chronological, historical narratives that help us understand Truman's motives and actions. These summaries are useful in emphasizing the highly political nature of the drive for civil rights in the United States in the mid-1940s through the early 1950s. Truman is convincingly portrayed as a principled populist whose dedication to the Constitution and sense of justice drove him to support the civil rights agenda, despite the backlash he received from opponents both within and outside of the Democratic Party. Shogan's savvy historical and detailed political analysis demonstrates how Truman overcame his own background, which included some not insignificant barriers to an appreciation of equal rights for minorities, including, among others, the fact that he was a grandson of slaveholders, associated for a time with the Ku Klux Klan, and had a history of racist remarks. Truman's long association with the Pendergast political machine tested his political acumen and allowed him to both appreciate and benefit from the art of coalition politics. In fact, Truman's entire political experience prepared him for representation of folks who would form the coalition of key constituencies that would ultimately lead to his upset victory in the 1948 presidential campaign, where African Americans played a central role. Shogan's efforts may seem to have been already rehearsed by others, perhaps most recently in Michael Gardner's Harry Truman and Civil Rights: Moral Courage and Political Risks (Carbondale: Southern Illinois University Press, 2002). But the key to the particular book under review here is that Shogan tempers Truman's moral courage with a well-defined analysis and explanation of Truman as an astute political operative driven by constitutional principles and a populist sense for defending the underdog. Truman's commitment to the rightness of the cause of civil rights for African Americans can also be traced back to his experiences with African American World War II veterans who returned home to violence and brutality as they sought to reintegrate themselves into civilian society. It was clear that Truman was also concerned about the public relations problem of promoting U.S.-style democracy in the international arena as a cornerstone in the emerging new Cold War, while basic human rights were being flouted routinely on the home front. Truman clearly felt the need to stanch this glaring inconsistency. Inaction would continue to solicit international opprobrium. Shogan argues that Truman matched words with action. His appointment of the President's Committee on Civil Rights resulted in a visionary document, To Secure These Rights, which the president used to introduce comprehensive civil rights legislation. And while he ultimately was unable to get a recalcitrant Congress to pass his legislation, he turned to executive action and the courts. …

Barriers strategic competitors grouping in the industrial sector

In article potential barriers of strategic grouping of competitors with reference to conditions of one of the branch markets of industrial sphere - a manufacture feather-down are designated. Pilot testing of heads and leading experts of the given sphere is with that end in view carried out. As it is necessary to apply a small number of barriers of strategic grouping of competitors to definition of strategic groups of competitors the most significant barriers of strategic grouping of competitors with reference to operating conditions of the enterprises of sphere a manufacture feather-down are revealed. Among them production degree of quality, the size of the enterprise, level of a diversification of manufacture, equipment the modern equipment of processing of raw materials, a degree of quality of integumentary materials, a price level, a degree of quality of used raw materials, width of assortment of production, a manufacture technological level, a personnel skill level. Elimination of insignificant barriers of strategic grouping is carried out by means of application of a way of expert estimations, namely ranging procedure. Are established relative weight of importance of barriers of strategic grouping of competitors in the designated branch market. Leaning against the allocated barriers it is necessary to carry out strategic segmentation of competitors of the branch market a manufacture feather-down. It will allow to define more accurately direct competitors for the enterprises of the given sphere and correctly to generate strategy of their competitive struggle.Â

Internal bags with barrier layers for foods packed in recycled paperboard: recent progress

Internal bags for packaging dry foods into boxes of recycled paperboard, collected in Dresden and Zurich in June 2013, were investigated with regard to the layer composition and the barrier efficiency against substances migrating from the recycled fibers. The layers were identified by microtome cuts and Fourier transform infrared spectroscopy, often after wet-chemical separation of the layers. The barrier efficiency was tested with five surrogate substances and classified between 1 and 5, with class 1 having no significant barrier effect, 4 being a virtually tight barrier consisting of polymeric material and 5 including an aluminum foil. Merely 17 of the 87 bags (20 %) consisted of paper or polyethylene that constituted insignificant barriers. Bags of oriented polypropylene, substantially reducing migration (class 2), were encountered in 32 % of the packs; those with more efficient, but still incomplete barriers (class 3) in 16 % and virtually tight barriers (classes 4 and 5) in 32 % of the products. This is a strong move toward efficient barriers compared to the findings in 2010. Efficient or tight barriers were found for nearly all food types, which suggests that there are no important technical obstacles against the inclusion of a barrier layer into all bags to protect the food against contamination from the recycled paper board.

Measurement of the Internal Orbital Alignment of Oligothiophene-TiO2 Nanoparticle Hybrids

X-ray photoemission spectroscopy (XPS), ultraviolet photoemission spectroscopy (UPS), and ultraviolet–visible spectroscopy (UV–vis) were used to investigate the electronic structure of the inner-molecule interface in oligothiophene-TiO2 organic molecule/nanoparticle hybrids. In these molecular structures the TiO2 nanoparticles were covalently bonded to the oligothiophene ligands. The discussed experiments utilized electrospray in-vacuum deposition, enabling the in situ characterization of these materials without the presence of significant ambient contamination. A comparison between the electronic structures of the individual molecular components of the hybrid with the assembled material enabled the determination of the orbital line-up at the internal interface of the hybrid molecules. Transmission electron microscopy (TEM) was used to investigate the morphology and size distribution of the nanoparticles. The results showed that the covalent bond causes an interface dipole at the junction between organic and inorganic parts of the hybrid. The dipole was determined to be 0.61 eV, and the hole injection barrier at the interface amounted to 0.73 eV. The electron injection barrier was estimated by taking into account the gap between highest occupied and lowest unoccupied molecular orbitals (HOMO, LUMO). This procedure suggested that there is only an insignificant barrier.

Electrochemistry on Multi-walled Carbon Nanotubes in Organic Solutions

The oxidation of ferrocene (FeCp2) to ferrocenium cation (\(\mbox{FeCp}_{2}^{+}\)) (where Cp: cyclopentadienyl anion, \(\mbox{C}_{5}\mbox{H}_{5}^{-}\)) was investigated by means of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) on either a glassy carbon (GC) electrode or a film consisted of multi-walled carbon nanotubes (MWCNT) in acetone (ACE), methanol (MeOH) and ACE/MeOH binary mixtures. The half-wave potentials (E1/2), the diffusion coefficients (D) and the heterogeneous electron transfer rate constants (ks) of the redox couple \(\mbox{FeCp}_{2}^{+/0}\) were determined. On both electrodes tested, the electron transfer process was found to be quasi-reversible and diffusion controlled in all investigated solvent mixtures. The E1/2 values were shifted toward less positive potentials with the enrichment of mixtures in MeOH, due probably to the larger Lewis basicity of the MeOH molecules. Furthermore, values of both D and ks diminish with the increase of MeOH content following the progressive increase of viscosity of the solvent medium. Among the electrodes probed, GC provides faster electrochemical process since it affords less charge-transfer resistance (Rct), and consequently, an insignificant barrier for interfacial electron transfer.

Electrochemical studies of the bis (triphenyl phosphine) ruthenium(II) complex, cis -[RuCl2(L)(PPh3)2], with L = 2-(2′-pyridyl)quinoxaline

Electrochemical studies of the newly synthesized bis(triphenyl phosphine) ruthenium(II) complex, cis-[RuCl2(L)(PPh3)2] (1, with L = 2-(2′-pyridyl)quinoxaline, C13N3H9), were performed in acetonitrile (ACN). For this purpose, cyclic voltammograms (CVs) as well as electrochemical impedance spectra (EIS) were recorded on either glassy carbon (GC), platinum (Pt), gold (Au), or multi-walled carbon nanotube (MWCNT) electrodes. Qualitative examination of solutions of 1 in ACN was performed on the basis of conductivity measurements and electrospray ionization mass spectrometry (ESI–MS). The conductivity data suggest that 1 is a 1 : 1 type electrolyte in ACN. The ESI spectra further demonstrate that upon dissolution of 1 in ACN progressive replacement of chloro- and PPh3-ligands by ACN occurs, leading to formation of [RuCl(L)(PPh3)(CH3CN)2]+Cl−, [2 + Cl − ]. The CVs recorded for [2 + Cl − ] on various working electrodes demonstrate that the reversibility of the redox couple 22 +/+ enhances with the order: Au < Pt < MWCNT < GC. The EI spectra verify that GC and MWCNT electrodes provide insignificant barrier for interfacial electron transfer since they afford less charge-transfer resistance.

Responses of global plant diversity capacity to changes in carbon dioxide concentration and climate

We model plant species diversity globally by country to show that future plant diversity capacity has a strong dependence on changing climate and carbon dioxide concentration. CO2 increase, through its impact on net primary production and warming is predicted to increase regional diversity capacity, while warming with constant CO2 leads to decreases in diversity capacity. Increased CO2 concentrations are unlikely to counter projected extinctions of endemic species, shown in earlier studies to be more strongly dependent on changing land use patterns than climate per se. Model predictions were tested against (1) contemporary observations of tree species diversity in different biomes, (2) an independent global map of contemporary species diversity and (3) time sequences of plant naturalisation for different locations. Good agreements between model, observations and naturalisation patterns support the suggestion that future diversity capacity increases are likely to be filled from a 'cosmopolitan weed pool' for which migration appears to be an insignificant barrier.

Mating between two hybridizing species,Viviparus aterandV. contectus(Mollusca: Prosobranchia)

The aquatic snailsViviparus aterandV.contectusare sympatric in several places in southern Europe; they differ morphologically, karyotypically and in their life-history traits. Previous work has shown weak introgression of allozyme markers associated with high heterospecific mating rates in a natural population at Lazise in Lake Garda, northern Italy. Snails were kept in small artificial ponds with equal numbers of males and females of both species, and rates of assortative mating, species-specific mating propensities, and the relative frequencies of the reciprocal heterospecific mating pairs (V.atermales×V.contectusfemales andV.contectusmales×V.aterfemales) were determined. Randomization tests were used to control statistically for problems inherent in many assortative mating experiments. The extent of assortative mating under relative densities of 50V.ater:1V.contectus, which is closer to the natural condition at Lazise, was also determined. Heterospecific matings occurred at a rate of 10·9% at relative densities of 1:1, significantly different from random mating. The heterospecific mating rate ofV.contectuswas much higher (75%) when it was at low density.Viviparus contectusfemales had significantly higher mating propensities than didV.aterfemales. In contrast to field data, the relative frequencies of the reciprocal heterospecific mating pairs were similar in the experiments, suggesting that factors other than mate choice may be responsible for the higher frequency ofV.atermales×V.contectusfemales in the field. Assortative mating inViviparuscomprises an insignificant barrier to introgression even in conjunction with the low fitness of hybrids, especially where the relative population densities in the species differ.

Measuring Thailand's barriers to investment

Capital market integration between Thailand on the one hand and Hong Kong, Japan, Singapore, the U.K. and the U.S. on the other is examined using the single-latent-variable test with investment barriers. Significant barriers to investment, ranging from 2.85 percent for a U.S. investor to 7.39 percent for a Japanese investor, are detected in the Second-Boom period of the Thai market. Insignificant barriers before the Second-Boom period may reflect low Thai stock returns and no asset trade.

Ion permeation through the L-type Ca2+ channel in rat phaeochromocytoma cells: two sets of ion binding sites in the pore.

1. Both inward and outward unitary Li+ currents through the L-type Ca2+ channel and discrete block of such currents by either internal or external Ca2+ are recorded. Detailed kinetic analyses are obtained for all of the four experimental configurations (internal or external Ca2+ block of either inward or outward Li+ currents). 2. No matter from which side the blocking Ca2+ ion comes, the exit (unblocking) rates are always the same at the same potential in the same direction of Li+ current flow. This indicates that the high-affinity Ca2+ binding site (the blocking site) is in the pore, and internal and external Ca2+ both go to the same site to produce the block. In other words, there can only be one high-affinity Ca2+ binding site or one set of such sites (sites separated by insignificant barriers) in the pore. Furthermore, the direction of exit of the blocking Ca2+ ion is always with, not against, the Li+ current flow. This suggests ion-ion interaction (the 'long pore effect') in the high-affinity sites. Therefore there must be more than one high-affinity site in the pore. Overall it is concluded that the pore must contain a set of high-affinity Ca2+ binding sites separated by insignificant energy barriers. 3. The voltage dependence of the off- (exit) rates is very similar in amplitude for all the four experimental configurations (e-fold change per approximately 25 mV depolarization or hyperpolarization). This strong voltage dependence in every configuration cannot be explained by any Ca2+ energy profile alone and must include a certain contribution from Li+. The mechanism underlying such a contribution seems to reside in the enhancement effect of Li+ on the exist of Ca2+. 4. The on-rates (blocking rates) for external Ca2+ are always fast no matter whether the Li+ currents are outward or inward. In certain cases the rates even approach the diffusion-controlled limit (approximately 10(9) M-1 S-1). This suggests that the high-affinity sites are very easily accessible from the outside, and probably there is no other ionic site located between the external pore mouth and the high-affinity sites. 5. The on-rates for internal Ca2+ are fast and voltage independent in outward Li+ currents, but are very slow and strongly voltage dependent in inward Li+ currents.(ABSTRACT TRUNCATED AT 400 WORDS)

Operating characteristics of rural non-farm enterprises in Central Province, Kenya

The ILO has identified seven characteristics which describe the operation of informal sector enterprises. These operating characteristics are assessed using survey data on rural non-farm enterprises located in market centers in Central Province, Kenya. Two characteristics (family ownership and small scale of operation) appear to be entirely true, but the remaining five are in need of qualification. Not all activities use labour-intensive technologies, indeed some require fairly large capital inputs. Indigenous resources are not important in many rural non-farm activities. Some important business skills are acquired inside the formal school system. There are not insignificant barriers to entering the more profitable non-farm enterprises. And these barriers, in conjunction with other factors, limit competition in some activities in many of the market centres. It appears that the operators of the more profitable and technically more advanced enterprises are forming a rural petty bourgeoisie. Thus contrary to the ILO interpretation, growth of the rural non-farm sector may be associated with greater income inequalities.