Perfect Sample Research Articles

Mechanical characteristics and thermal conductivity of defect single-layer buckled honeycomb germanene

This study uses molecular dynamics (MD) simulation to investigate the defect rate, defect morphology, and different temperature effects on the mechanical properties, deformation behavior, and thermal conductivities of a single layer of germanene nanosheets via a tensile process. Samples are squeezed in the middle, leading to filling in minor defects. Young’s modulus and yield strength decrease with increasing temperature and defect rates. Young’s modulus in the armchair direction is larger than that in the zigzag direction, with the samples with a random porosity of 0%and 2% and smaller than the model with a random porosity of 4% to 10%. Young’s modulus in the armchair direction is larger than in the zigzag order with all the different pore shapes. The yield strength in the armchair direction is smaller than that in the zigzag at all temperatures, all different pore shapes, and all defect rates except for the sample with a random porosity of 2%. The thermal conductivity depends on the sample direction, the defect morphologies due to the shrinkage of membranes are complicated, and all are smaller than the thermal conductivity of a perfect sample. The thermal conductivity of the perfect sample is highest at 300 K.

Powder bed fusion repair of titanium with surface damage: Molecular dynamics study on microstructure and mechanical properties

Additive manufacturing has been emerging as a highly efficient method that minimizes the consumption of virgin materials and energy to rapidly repair the damaged parts and potentially recover the original performance. Here, the microstructures and mechanical properties of polycrystalline titanium (Ti) with surface damage after powder bed fusion (PBF) repair and post-polishing treatment are investigated by molecular dynamics simulations. It is found that during PBF repair of the surface damage by melting Ti nanoparticles, grain boundaries (GBs) in polycrystalline Ti are more susceptible to damage from temperature elevation than the grain interiors. During the solidification process, grains grow in the form of columnar crystals. After PBF repair and post-polishing treatment, the yield strength of damaged samples is recovered to 96.8% of that of perfect ones. This restoration can be attributed to the increased capacity of carrying dislocations due to that the GB directional growth generates dislocation walls after PBF repair. More importantly, the flow stress exceeds that of the perfect sample due to the increase in stacking faults and the appearance of twins after PBF repair, which enhance the resistance of dislocation motion. The fatigue performance of the damaged samples processed by combinatorial PBF repair and post-polishing treatment is found to surpass that of perfect samples. This is attributed to that the elimination of rough surface and the reduction of intragranular dislocations avoid dislocation entanglement that otherwise results in strain concentration, and also prevent the premature occurrence of twins and the rapid increase in stacking faults during the cyclic loading, thus retarding the nucleation of intergranular cracks. Our molecular dynamics simulation results could help shed light on the atomic mechanism of microstructure evolution during PBF repair and mechanical performance after PBF repair.

The maternal epigenome as a window into the in utero environment that the foetus experiences

Maternal stress pre-pregnancy and exposure to stress in utero has life-long negative consequences for the developing foetus. There is growing evidence that this passes through changes in foetal epigenetic markers such as DNA methylation. We hypothesize that the mother’s prior life experience and changes in her external environment will change the in utero environment she provides to the developing foetus, and both will be reflected in changes to the mother’s epigenome. As classical dogma states that during embryo all DNA methylation marks are removed and replaced de novo, this raises the question as to how to assess the in utero environment, examining the role it plays in the transmission of environmental cues. We suggest that the maternal epigenome can act as a proxy for the developmental environment she provided to her offspring in utero; this developmental environment determines the child’s epigenome and lifelong health trajectory. Furthermore, we suggest that the maternal origin of the placental decidua make this the perfect sample for assessing the in utero environment in the context of the mothers’ prior life experience, mediating maternal exposure to infant phenotype.

Learning to Select Pivotal Samples for Meta Re-weighting

Sample re-weighting strategies provide a promising mechanism to deal with imperfect training data in machine learning, such as noisily labeled or class-imbalanced data. One such strategy involves formulating a bi-level optimization problem called the meta re-weighting problem, whose goal is to optimize performance on a small set of perfect pivotal samples, called meta samples. Many approaches have been proposed to efficiently solve this problem. However, all of them assume that a perfect meta sample set is already provided while we observe that the selections of meta sample set is performance-critical. In this paper, we study how to learn to identify such a meta sample set from a large, imperfect training set, that is subsequently cleaned and used to optimize performance in the meta re-weighting setting. We propose a learning framework which reduces the meta samples selection problem to a weighted K-means clustering problem through rigorously theoretical analysis. We propose two clustering methods within our learning framework, Representation-based clustering method (RBC) and Gradient-based clustering method (GBC), for balancing performance and computational efficiency. Empirical studies demonstrate the performance advantage of our methods over various baseline methods

خانگی نظامِ حیات پر کرونا وائرس کے اثرات:سیرت النبی ﷺکی روشنی میں تجزیاتی مطالعہ

Family system of life has been given a lot of importance in the Seerat-un-Nabi ﷺ. The survival of family system is the backbone for the survival and safety of human society. During the epidemic of Corona virus, the human has faced many changes. Due to this virus, human life has suffered severe anxiety in all areas of life. While other aspects of life have been affected by this virus, it has also had numerous effects on the family system. These impacts include both positive and negative impacts. These include spousal relationships, parent-child relationships, and sibling relationships, which include aspects such as psychological, emotional, and behavioral aspects of human disposition. In all these angles positive and negative changes took place. All these qualities of an individual must affect all the roles of the family system in some degree. Seerat-un-Nabi ﷺ is a perfect Sample of life. During the epidemic of corona virus, we had to go through various kinds of bitter experiences. Seerat-un-Nabi ﷺ provides us with solutions to difficult-to-difficult situations and complicated to complicated problems. In this article, an attempt has been made to ensure that guidance is derived from the Seerat-un-Nabi ﷺ to deal with such situations, so that in the future, in such a situation, May the clear instructions of the Seerat-un-Nabi ﷺ be in front of us, by following which we can lead a peaceful life.

Sustainability innovation index for micro, small and medium enterprises and their support ecosystems based on an empirical study in India

Competitiveness of a country depends on the innovation capacity of its industries while sustainability relies upon the adoption of cleaner production processes. Hence, to promote economic development without negative environmental impact, it is imperative to have appropriate development policies and also a sound instrument to monitor the effectiveness of the supporting ecosystem. India, one of the world's largest economies with a huge base of Micro, Small, and Medium Enterprises (MSMEs), makes it a perfect sample for creating an Index to measure innovation for sustainability and adds to the empirical literature. The study identifies the determinants of innovation and the key drivers using multivariate tools on the empirical data collected from the MSMEs in 4 key sectors that have Social, Economic, and Environmental relevance. The findings suggest that “Market sources” is the most influential determinant of innovation, followed by “Institutional sources”, “Market sophistication” and “Business Membership Organisations”. Further, findings of the Principal Component Analysis revealed that “Productivity and Profitability” consideration is the most important driver for adoption of innovation for sustainability by MSME units. The other drivers are “Regulatory and Occupational Health and Safety Needs”; “Immediate Survival Needs”; “Raw Material and other Cost Issues”; “Developmental Support”, and “Competition from Similar Units”. Based on the relative importance of these factors, an index is created to measure the effectiveness of the innovation ecosystem. The paper also suggests the use of this index to assess the strength of the ecosystem at the national, sectoral, regional or state, and district or cluster level. This study offers promising avenues for future research ideas for evidence-based policy formulation.

Fabrication of a Superhydrophobic SiO2 Coating with Anticorrosive Protection

AbstractIn this work, the carbon steel matrix obtained a silane coupling agent (KH550) modified rough SiO2 coating, covering it by dip‐coating method. The modified SiO2 (K‐SiO2) coating on the carbon steel was coated with stearic acid (STA) and adjusted the proportion of SiO2 nanoparticles and KH550 to achieve the more perfect superhydrophobic sample. It turns out that SiO2 particles were evenly disturbuted and linked together by KH550 to form a stable structure. The K‐SiO2 coating liquid was further added a modifier of STA to achieve low surface energy, and then developed a durable and corrosion resistant coating. The superhydrophobic coating liquid was coated on the carbon steel to obtain a multifunctional superhydrophobic coating (contact angle=163°, rolling angle=1.4°), having excellent self‐cleaning, adhension, durability and corrosion resistance.

Atomistic understanding of the influences of defects on the spall damage of aluminum under multiple shock loadings

The spall damage of solid single crystal Al with initial defects such as voids or He bubbles under multiple decaying shock loadings is studied by molecular dynamics simulations. After the first shock compression and release, plenty of sparse defects in the void collapsed regions and a few disordered atoms surrounding He bubbles are formed in the Al-void and Al–He samples, respectively. The spall mechanism for the Al-void sample is the nucleation–growth–coalescence of voids originated from the defects at the early stage of damage and from the regions without defects at the late stage. Under second shock loading, the first spall region is compressed and the compression extent is dependent on the shock intensity; however, the density after complete compression is lower than the initial value. Meanwhile, a new spall region is formed due to the interaction of the second incident rarefaction wave with the one reflected from the surface of the first spall region into the sample, when the shock intensity is relatively strong. The new spall region exhibits lower spall strength for the samples with initial defects than that for the perfect sample. Additionally, respallation occurs in the first spall region after compression under the strong second shock, its damage evolution is strongly influenced by the defects formed after compression, and the spall strength is much lower than that of first spallation. For the Al–He sample, the spall mechanism is always dominated by the expansion-merging of He bubbles, with the fastest damage development and the lowest spall strength.

Utilization of Denim Waste into Debric Board

More than one billion pieces of denim are sold every year. The consumptions from North America are 39%, West Europe 20%, East Asia 20%, and the rest of it, including Indonesia, is 13%. This study aims to know the comparation between denim waste become particle boards toward SNI as a national standard through several variables. The variables are water content, thickness increment, density, acidity, and alkalinity resistance. Making the sample refers to the particle board-making process, such as preparation, mixing, gluing, pressing, and drying. On the other hand, this study’s method for the test is based on SNI 03-2105-2006 about Particle Board and SNI 01-7201-2006 Plywood and Beautiful Paper-faced Blockboard. The sample test divided by four ratios, 100%:100% (a), 75%:25% (b), 50%:50% (c), and 25%:75% (d). The result of this study showed that the water content test is the only variable influenced by the sample’s ratio. At the same time, sample A is the perfect sample with a ratio of 100% because sample A complied with the water content, thickness test, density test, and minor damage on acidity and alkalinity resistance test. It can conclude that denim waste has the potential to be improved as interior materials such as particle board.

Marketing in a crisis: lessons from the “COVID election” in New Zealand

PurposeThis paper aims to identify both the traditional and novel forms of marketing behind New Zealand Prime Minster Jacinda Ardern’s landslide victory in the 2020 New Zealand General Election during the COVID-19 pandemic.Design/methodology/approachThis research analysed both qualitative and quantitative data, including over 70 primary sources, the perspectives of practitioners, polling and data from surveys with over 450,000 respondents. The qualitative data was analysed interpretively against established theoretical concepts, whereas the quantitative data was analysed through descriptive statistics.FindingsThis research found that COVID-19 drastically changed what the public prioritised, allowing Ardern and Labour to position themselves as guardians of government stability, while camouflaging previous delivery failures. Labour also used a more emergent market-oriented and “polite” populist political marketing strategy.Research limitations/implicationsWhile the survey data used is not a perfect sample of the population, it is the largest public opinion survey in New Zealand and, given its convergence with other sources, provides valuable insights into political marketing during a crisis more broadly.Practical implicationsThis research reinforces marketing’s most important aspect; the market should drive action. How decision makers respond to the market should depend on the environment. Thus, up-to-date market research becomes even more important during a crisis, as the environment changes rapidly. This leaves prior assumptions obsolete and implies strategy needs to be adaptive. Additionally, greater public attention provides governing leaders with the opportunity to present a more well-rounded leadership image.Originality/valueTo the best of the authors’ knowledge, this is the first research to look at marketing while in government and election campaigning in the context of successful management of a global pandemic.

Perfect Sampling in Infinite Spin Systems Via Strong Spatial Mixing

We present a simple algorithm that perfectly samples configurations from the unique Gibbs measure of a spin system on a potentially infinite graph $G$. The sampling algorithm assumes strong spatial mixing together with subexponential growth of $G$. It produces a finite window onto a perfect sample from the Gibbs distribution. The run-time is linear in the size of the window, in particular it is constant for each vertex.

Does the Two-Child Policy Affect the Consumption Upgrade of “Two-Child Families”: Based on CFPS Data from the Chinese Family Tracking Survey

Purpose – In the context of the continued low consumption rate of Chinese residents, the increasingly aged society in China, and the decline in the birth rate, the Chinese government has gradually liberalized the fertility policy. The twochild policy has undergone policy adjustments from “only child of both parties” in 2011 to “only child of one party” in 2014, and then to the “Universal” policy in 2016, which marked the complete end of the “one-child policy” implemented since the 1970s. The purpose of this paper is to assess the effect of the “two-child birth policy” on the consumption upgrading of urban households, and to explore the mechanism of the effect. Design/Methodology/Approach – Through the quasi-natural experiment of the “two-child policy”, empirical analysis is carried out using the panel data of the China Family Tracking Survey (CFPS) database from 2012-2018. In order to improve sample selection bias and endogenous problems as much as possible, double-difference (PSM-DID) methods based on propensity score matches were adopted to construct the experimental and control groups to empirically test the impact of the second-child policy. A robustness test was carried out through methods such as parallel trend tests and sample size reduction. Further heterogeneity analysis of the policy action mechanism was conducted using the triple difference method (DDD). Findings – (1) In general, the “two-child policy” has promoted the upgrading of household consumption levels and consumption structures. (2) Furthermore, research findings of a triple difference (DDD) model were that the effect of fertility policy between household consumption levels and consumption structure was different across target households with different levels of household wealth. That is, the higher the wealth level of the household, the more the fertility policy promoted an increase in household consumption and an upgrade of the consumption structure, but for education consumption expenditure, regardless of household wealth level, the fertility policy promoted a significant increase in household consumption expenditure and had a “crowding out effect” on other developmental hedonic consumption of the household, and the lower the wealth level, the more pronounced the crowding-out effect. Research Implications – This paper studies the consumption of urban residents from the perspective of the characteristics of family population structure. It uses Chinese empirical data to test the applicability of relevant consumption theories in China, and provides perfect unique sample data for the academic community. By exploring the mechanism of the impact of the fertility policy on the consumption level and structure of residents, it can provide a reference for evaluating past population and economic policies. However, it provides a theoretical basis and guidance for the formulation of population and economic policies in the future, and the implementation of supporting policies for the “Three-Child Policy”.

A modified social spider algorithm for an efficient data dissemination in VANET.

Technical growth in the field of communication and information is an important aspect in the development and innovation of industrial automation and in the recent advances in the field of communications. The recent development of mobile communications has led to worldwide ubiquitous information sharing and has rehabilitated human lifestyles. This communication revolution is now introducing effective information sharing into the automotive industry. The current technology is extending this field of applications for vehicle safety, improving the efficiency in traffic management, offering reliable assistance for drivers and supporting the modern field of vehicle design. With these advances, the vehicular network concept has grabbed worldwide attention. In this article, a novel sampling-based estimation scheme (SES), to initiate the involvements and increase the probabilistic contacts of vehicle communication. The scheme is divided into a few segments, for ease of operations with a perfect sample. The contact duration between two vehicles moving in opposite directions on their overlapped road is lower, but their contact probability is higher. By contrast, the duration of the contact between two vehicles moving in the same direction on their overlapped road is higher, but their contact probability is lower. SES can easily obtain efficient routing by considering the above-mentioned stochastic contacts. Furthermore, we investigate the content transmission among the probabilistic contacts, by using the flow model with probabilistic capacities. The performance of the proposed SES is experimentally validated with the probabilistic contacts in VANETs.

Understanding deep learning (still) requires rethinking generalization

Despite their massive size, successful deep artificial neural networks can exhibit a remarkably small gap between training and test performance. Conventional wisdom attributes small generalization error either to properties of the model family or to the regularization techniques used during training. Through extensive systematic experiments, we show how these traditional approaches fail to explain why large neural networks generalize well in practice. Specifically, our experiments establish that state-of-the-art convolutional networks for image classification trained with stochastic gradient methods easily fit a random labeling of the training data. This phenomenon is qualitatively unaffected by explicit regularization and occurs even if we replace the true images by completely unstructured random noise. We corroborate these experimental findings with a theoretical construction showing that simple depth two neural networks already have perfect finite sample expressivity as soon as the number of parameters exceeds the number of data points as it usually does in practice. We interpret our experimental findings by comparison with traditional models. We supplement this republication with a new section at the end summarizing recent progresses in the field since the original version of this paper.

Spatially Resolved Determination of Metallization-Induced Recombination Losses Using Photoluminescence Imaging

Metallization induced recombination losses are one dominant loss mechanism for current industrial solar cells. A precise determination of these losses is important for contacting technology optimization, as well as precise solar cell modeling. Usually, for state-of-the-art approaches to determine j <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0,met</sub> , it is assumed that the samples itself exhibit spatially uniform properties (e.g., carrier lifetime or sheet resistance) or that the used reference samples are identical to the metallized samples. Finally, in most cases, only one global j <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0,met</sub> -value for the entire sample is given, neglecting possible spatial inhomogeneities. In this article, we mostly eliminate the necessity for the assumptions of perfect sample homogeneity by means of an interpolation scheme of the photoluminescence (PL) signal. Thereby, we can predict the PL signal of a virtually nonmetallized test field with a relative standard deviation of about σ ≈ 0.7%. Additionally, we determine j <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0,met</sub> for specific test fields at different positions on the sample and correlate the results to the local emitter sheet resistance R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sh</sub> , the local peak firing temperature of the sample during the fast firing process T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">peak</sub> , and the test field finger spacing d. For our samples, a reduction of d from d = 1000 μm to d = 200 μm leads to a reduction of j <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0,met</sub> by up to 18%. This strong effect is physically unexpected and so far not considered by the state-of-the-art approach, frequently performed in the photovoltaic community. Further, we perform a sensitivity and error analysis which reveals that we are able to determine j <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0,met</sub> within an estimated accuracy between 15% and 18%.

Quantification of Intrafraction and Interfraction Tumor Motion Amplitude and Prediction Error for Different Liver Tumor Trajectories in Cyberknife Synchrony Tracking

To research the fiducial-based, real-time tracking intrafraction (during the fraction [intra-]) and interfraction (between fractions [inter-]) tumor respiration amplitude, motion trajectory, and prediction error and quantify their relationships for different types of motion trajectories during Cyberknife-based stereotactic ablation radiotherapy. Twelve patients with liver tumors were treated using a Cyberknife system, and 58 fractions were involved in this study. Real-time target motion tracking data were extracted and transformed from the robot coordinate system into the patient coordinate system by the rotation matrix. Only the time sessions of the beam on were studied according to the data information generated from the Cyberknife motion tracking system. The motion correlation model between the external marker signal and internal fiducial position was built to present the type of motion trajectory. Using the correlation model as a function of external marker signal and internal fiducial position, we knew 4 motion trajectories mainly existed for liver cancer patients as follows: perfect linearity (group I), simple linearity (group II), hysteresis (group III), and area respiratory (group IV) patterns. More than half of the patients had a linear breathing trajectory. Analyzing all patients together, the intra-amplitudes were slightly less than those of the inter-amplitudes. The amplitude from large to small was in the superior-inferior, left-right and anterior-posterior directions, regardless of inter- and intra-amplitudes. Then, patients with a larger peak-to-peak have a larger standard deviation of amplitude and a larger amplitude in all fractions/sessions. The prediction errors of the linear motion trajectory were generally less than 1 mm. The prediction errors of the regular hysteresis breathing model were smaller than those of the irregular hysteresis model. Scattered breathing would result in a larger tracking error, such as the area respiratory trajectory. It was logical that prediction errors were larger for patients who showed much variation in their breathing amplitude. This paper showed that the liver motion trajectory model included perfect linearity, sample linearity, hysteresis, and area. The linear motion trajectory presented the minimum tracking error and the best stability, and the hysteresis and area trajectory were the worst. Therefore, breathing management, including respiration training, control, and evaluation of motion trajectory in all directions, was significantly necessary during liver SABR treatment.

Perfect sampling for Gibbs point processes using partial rejection sampling

We present a perfect sampling algorithm for Gibbs point processes, based on the partial rejection sampling of Guo, Jerrum and Liu (In STOC’17 – Proceedings of the 49th Annual ACM SIGACT Symposium on Theory of Computing (2017) 342–355 ACM). Our particular focus is on pairwise interaction processes, penetrable spheres mixture models and area-interaction processes, with a finite interaction range. For an interaction range $2r$ of the target process, the proposed algorithm can generate a perfect sample with $O(\log(1/r))$ expected running time complexity, provided that the intensity of the points is not too high and $\Theta(1/r^{d})$ parallel processor units are available.

Cosmology with the submillimetre galaxies magnification bias: Proof of concept

Context. As recently demonstrated, high-z submillimetre galaxies (SMGs) are the perfect background sample for tracing the mass density profiles of galaxies and clusters (baryonic and dark matter) and their time-evolution through gravitational lensing. Their magnification bias, a weak gravitational lensing effect, is a powerful tool for constraining the free parameters of a halo occupation distribution (HOD) model and potentially also some of the main cosmological parameters. Aims. The aim of this work is to test the capability of the magnification bias produced on high-z SMGs as a cosmological probe. We exploit cross-correlation data to constrain not only astrophysical parameters (Mmin, M1, and α), but also some of the cosmological ones (Ωm, σ8, and H0) for this proof of concept. Methods. The measured cross-correlation function between a foreground sample of GAMA galaxies with spectroscopic redshifts in the range 0.2 &lt; z &lt; 0.8 and a background sample of H-ATLAS galaxies with photometric redshifts &gt; 1.2 is modelled using the traditional halo model description that depends on HOD and cosmological parameters. These parameters are then estimated by performing a Markov chain Monte Carlo analysis using different sets of priors to test the robustness of the results and to study the performance of this novel observable with the current set of data. Results. With our current results, Ωm and H0 cannot be well constrained. However, we can set a lower limit of &gt; 0.24 at 95% confidence level (CL) on Ωm and we see a slight trend towards H0 &gt; 70 values. For our constraints on σ8 we obtain only a tentative peak around 0.75, but an interesting upper limit of σ8 ≲ 1 at 95% CL. We also study the possibility to derive better constraints by imposing more restrictive priors on the astrophysical parameters.

INFLUENCE OF PLANTING SPACES ON GROWTH, YIELD AND BACTERIAL SOFT ROT INFECTION OF LETTUCE (Lactuca sativa L.)

The experiment was conducted to evaluate the growth, yield, and bacterial soft rot infection of Lettuce (Lactuca sativa L.) in the organic system of the multispan house without chemical fertilization and without heating, planting was in different planting spaces. The research was directed from 14th November (sowing seeds in the nursery) 2018 to 14th of March 2019 (harvesting). The experiment was designed in randomized complete blocks (RCBD), with eight treatment planting spaces 10, 15, 20, 25, 30, 35, 40, 45cm planting spaces, the cultivars (TERESA) were used in the experiment, with four replication for each treatment. The obtained results were analyzed averages were compared by Duncan Multipliers and the least significant difference(LSD) at the possibility&gt;0.05 level. The evaluated characteristics in this experiment were marketable fresh weight per plant, per square meter, plant height, number of leaves, plants infected with soft rot, roots length, outlet leaves, and number of heads. The highest fresh weight 511.3 gr plant, the highest number of leaves/plant 39.4l, root length 9.1 cm, leaf length 31.3 cm obtained with the wide spacing, but the highest yield 10671.4 gm/m2 and plant height were obtained with the smaller spacing 10.15 cm. Lettuce may present a yield decrease due to the occurrence of lettuce soft rot disease caused by Pectobacterium carotovorum subsp. carotovorum. This study was designed to determine the perfect sample size for evaluating disease occurrence in fields in the last spring months to collect and store heads. The soft rot infection percent was higher in low spacing 3% because the high densities of plants make contact with the plants and lowest or no infection in high spacing.

Study on the mechanical and thermal properties of poly(lactic acid)/office waste paper fiber composites

AbstractEnvironment friendly composites with favorable mechanical properties and low water absorption performance were successfully produced from poly(lactic acid) (PLA), office waste paper fiber (OWF), and coupling agents. The perfect sample was easily manufactured by melting–blending and injection molding. The PLA/OWF composites were comparable with other PLA/plant fiber composites, and the results indicated that the PLA/OWF composites show better performance than PLA/wheat straw fiber composites and PLA/bamboo fiber composites. On this basis, influence of modification of OWF on the properties of composites was investigated. The infrared results show that the OWF modification by different coupling agents was successful, and the scanning electron microscopy indicates that prepared composites exhibit good interfacial compatibility due to preferable binding force between fiber and matrix. With addition of 2 wt% γ‐(2,3‐propylene oxides)propyl trimethylsilane, the composite exhibits high tensile strength of 58.96 MPa, reflecting increase of 14% than the pure PLA. According to the crystallization and melting performance table, OWF can act as nucleating agent to promote the crystallization properties on composites, while the coupling agents have little effect on thermal stability. This article confirmed that the OWF has appropriate properties and is suitable for preparing composite materials and this work provides a novel idea for the utilization of office waste paper.