The overview describes the synergy between biological sciences and cellular structures processed by additive manufacturing to elucidate the significance of cellular structured implants in eliminating ...stress shielding and in meeting the bio-mechanical property requirements of elastic modulus, impact resistance, and fatigue strength in conjunction with the biological functionality. The convergence of additive manufacturing, computer-aided design, and structure-property relationships is envisaged to provide the solution to the current day challenges in the biomedical arena. The traditional methods of fabrication of biomedical devices including casting and mechanical forming have limitations because of the mismatch in micro/microstructure, mechanical, and physical properties with the host site. Additive manufacturing of cellular structured alloys via electron beam melting and laser powder bed fusion has benefits of fabricating patient-specific design that is obtained from the computed tomography scan of the defect site. The discussion in the overview consists of two aspects – the first one describes the underlying reason that motivated 3D printing of implants from the perspective of minimising stress shielding together with the mechanical property requirements, where the mechanical properties of cellular structured implants depend on the cellular architecture and percentage cellular porosity. The second aspect focuses on the biological response of cellular structured devices.
Abstract
Identification of gamma-ray burst (GRB) progenitors based on the duration of their prompt emission (
T
90
) has faced several roadblocks recently. Long-duration GRBs (with
T
90
> 2 s) have ...traditionally been thought to be originating from the collapse of massive stars and the short-duration ones (with
T
90
< 2 s) from compact binary mergers. However, recent observations of a long GRB associated with a kilonova (KN) and a short GRB with supernova association demand a more detailed classification of the GRB population. In this Letter, we focus on GRBs associated with KNe, believed to be originating from mergers of binaries involving neutron stars (NSs). We make use of the GRB prompt-emission light curves of the Swift/BAT 2022 GRB catalog and employ machine-learning algorithms to study the classification of GRB progenitors. Our analysis reveals that there are five distinct clusters of GRBs, of which the KN-associated GRBs are located in two separate clusters, indicating they may have been produced by different progenitors. We argue that these clusters may be due to subclasses of binary neutron star and/or NS–black hole mergers. We also discuss the implications of these findings for future gravitational-wave observations and how those observations may help in understanding these clusters better.
It is important for a robot to be able to interpret natural language commands given by a
human. In this paper, we consider performing a sequence of mobile manipulation tasks with
instructions ...described in natural language. Given a new environment, even a simple task
such as boiling water would be performed quite differently depending on the presence,
location and state of the objects. We start by collecting a dataset of task descriptions
in free-form natural language and the corresponding grounded task-logs of the tasks
performed in an online robot simulator. We then build a library of verb–environment
instructions that represents the possible instructions for each verb in that environment,
these may or may not be valid for a different environment and task context. We present a
model that takes into account the variations in natural language and ambiguities in
grounding them to robotic instructions with appropriate environment context and task
constraints. Our model also handles incomplete or noisy natural language instructions. It
is based on an energy function that encodes such properties in a form isomorphic to a
conditional random field. We evaluate our model on tasks given in a robotic simulator and
show that it successfully outperforms the state of the art with 61.8% accuracy. We also
demonstrate a grounded robotic instruction sequence on a PR2 robot using the Learning from
Demonstration approach.
The study focuses on the significant effects of carbon and alloying elements on variant selection during martensite transformation and its influence on toughness. 0.17C steel with low content of ...alloying elements and 0.13C steel with relatively higher alloying content were studied. The strength of quenched 0.13C steel was inferior to 0.17C steel, and their yield strengths were 894 and 999 MPa, respectively. However, −40 °C Charpy impact energy of 0.17C and 0.13C steels was 40 and 198 J, respectively. An analysis by electron backscattered diffraction (EBSD) underscored that a larger proportion of V1/V2 variant pairs and a lower content of V1/V4 variant pairs in 0.13C steel reduced the residual stress, thereby significantly enhancing the toughness of steel. In addition, the high density of high angle grain boundaries (HAGBs, especially V1/V2 variant pairs) had the ability to hinder crack propagation, which further toughens the matrix.
The effect of load models on distributed generation (DG) planning in distribution system is investigated in this work. It is shown that load models can significantly affect the DG planning. Normally ...a constant power (real and reactive) load model is assumed in most of the studies. Such assumptions may lead to inconsistent and misleading results about deferral values, loss reduction, payback period, and other subsequent calculations. It has been demonstrated that DG planning based on such assumptions would not be effective after implementation. It is shown that load models can significantly affect the optimal location and sizing of DG resources in distribution systems. A comparative study of real and reactive power loss, real and reactive power intake at the main substation and MVA support provided by installing DG resources for different type of loads models has been performed.
The development of robust nano‐ and microstructured catalysts on highly conductive substrates is an effective approach to produce highly active binder‐free electrodes for energy conversion and ...storage applications. As a result, nanostructured electrodes with binder‐free designs have abundant advantages that provide superior electrocatalytic performance; these include more exposed active sites, large surface area, strong adhesion to substrates, facile charge transfer, high conductivity, high intrinsic catalytic activity, and fine‐tuning of its electronic nature through nanostructure modification. Notably, the interface chemistry of an electrocatalyst plays a significant role in their optimized electrocatalytic activity and stability. This review provides an overview of recent progress in nano‐ and microstructured catalysts, such as one, two, and 3D catalysts as binder‐free electrodes for electrocatalytic water splitting via the hydrogen evolution reaction and oxygen evolution reaction, and beyond. Furthermore, this review focuses on the current challenges and synthesis strategies of binder‐free electrodes, with a focus on the impact of nanostructure on their functional property relationships and enhanced bifunctional electrocatalytic performance. Finally, an outlook for their future advances in energy conversion and storage is provided.
The development of robust 1D, 2D, and 3D structured binder‐free electrodes with designed properties and architectures has led to advances in bifunctional electrocatalytic water splitting, photoelectrochemical water splitting, and photocatalysis. This review highlights the state‐of‐the‐art of binder‐free nano‐ and microstructures, from approaches based on well‐regulated fabrication to their successful application for electrocatalytic hydrogen evolution reaction/oxygen evolution reaction and photocatalysis.
Three‐dimensional (3 D) perovskite has attracted a lot of attention owing to its success in photovoltaic (PV) solar cells. However, one of its major crucial issues lies in its stability, which has ...limited its commercialization. An important property of organic–inorganic perovskite is the possibility of forming a layered material by using long organic cations that do not fit into the octahedral cage. These long organic cations act as a “barrier” that “caps” 3 D perovskite to form the layered material. Controlling the number of perovskite layers could provide a confined structure with chemical and physical properties that are different from those of 3 D perovskite. This opens up a whole new batch of interesting materials with huge potential for optoelectronic applications. This Minireview presents the synthesis, properties, and structural orientation of low‐dimensional perovskite. It also discusses the progress of low‐dimensional perovskite in PV solar cells, which, to date, have performance comparable to that of 3 D perovskite but with enhanced stability. Finally, the use of low‐dimensional perovskite in light‐emitting diodes (LEDs) and photodetectors is discussed. The low‐dimensional perovskites are promising candidates for LED devices, mainly because of their high radiative recombination as a result of the confined low‐dimensional quantum well.
Peeling back the layers: The synthesis, properties, and structural orientation of low‐dimensional perovskite are surveyed. Controlling the number of perovskite layers can provide a confined structure with chemical and physical properties that are different from those of 3 D perovskite. The use of low‐dimensional perovskite in photovoltaic solar cells is discussed, as is its use in light‐emitting diodes and photodetectors.
The North-eastern (NE) India, comprising of Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim and Tripura, possess diverse array of locally adapted non-Basmati aromatic ...germplasm. The germplasm collections from this region could serve as valuable resources in breeding for abiotic stress tolerance, grain yield and cooking/eating quality. To utilize such collections, however, breeders need information about the extent and distribution of genetic diversity present within collections. In this study, we report the result of population genetic analysis of 107 aromatic and quality rice accessions collected from different parts of NE India, as well as classified these accessions in the context of a set of structured global rice cultivars. A total of 322 alleles were amplified by 40 simple sequence repeat (SSR) markers with an average of 8.03 alleles per locus. Average gene diversity was 0.67. Population structure analysis revealed that NE Indian aromatic rice can be subdivided into three genetically distinct population clusters: P1, joha rice accessions from Assam, tai rices from Mizoram and those from Sikkim; P2, aromatic rice accessions from Nagaland; and P3, chakhao rice germplasm from Manipur corrected. Pair-wise FST between three groups varied from 0.223 (P1 vs P2) to 0.453 (P2 vs P3). With reference to the global classification of rice cultivars, two major groups (Indica and Japonica) were identified in NE Indian germplasm. The aromatic accessions from Assam, Manipur and Sikkim were assigned to the Indica group, while the accessions from Nagaland exhibited close association with Japonica. The tai accessions of Mizoram along with few chakhao accessions collected from the hill districts of Manipur were identified as admixed. The results highlight the importance of regional genetic studies for understanding diversification of aromatic rice in India. The data also suggest that there is scope for exploiting the genetic diversity of aromatic and quality rice germplasm of NE India for rice improvement.
Deccan volcanic units cover vast region in west-central India and host some of the monumental geoheritage sites. These basalt units are not suitable either for excavation or sculpturing, because of ...inherent cooling cracks. Weathering of iron minerals also reduces their utilization for work of art. From the beginning of first century, ancient artisans have identified thermally baked zones in the vicinity of lava tubes, channels and effusive centres. Newly formed rocks within these zones are indurated, hardened and excellent for excavation, sculpturing and polishing. The degree of induration is also skilfully utilized, black basalt has acquired vibrant shades of red by amalgamating iron minerals. Depending on religious believes, Hindus excavated enormous Kailash temple from the top of the hill with intricate sculpturing of idols and statues, while Buddhists excavated large meditation halls (Vihars) with columns and arches. We identified hidden effusive centre in the vicinity of Ellora cave complex. Physical volcanic feature such as portal portion of lava tube is utilized for locating large Saptashrungi temple. Silica rich agglomerate basalt, with large fragments is used for coarse carving of tall Buddha statue, corresponding with the sixth-century Bamiyan caves in Afghanistan, while exceedingly fine-grained agglomerate is preferred for intricate carving of Shiva idol in Elephanta caves. Damage by invaders and erosion are usually repaired by cement and concrete, losing aesthetic sense. We recommend matching rocks for restoration and use of red ochre, blue and green (azurite and malachite) from copper and brown from bark extract for cave paintings.
The effect of sole application of inorganic fertilizers (NPK) (N:P:K:: 30:26:25
kg
ha
−1) and combined application of farmyard manure (FYM) @ 4
Mg
ha
−1 and inorganic fertilizers (NPK
+
FYM)
...vis-a-vis non-application of fertilizers and manures (control) on changes in soil physical properties and plant growth characteristics of soybean (cv. JS 335) was studied in a deep Vertisol at the Indian Institute of Soil Science, Bhopal during the year 2001–2004. The results indicated that conjunctive use of recommended dose of fertilizer and farmyard manure (NPK
+
FYM) resulted in significant (
P
<
0.05) decrease of bulk density (9.3%), soil penetration resistance (42.6%) and increase in hydraulic conductivity (95.8%) and mean weight diameter of the water stable aggregates (13.8%) and soil organic carbon content (45.2%) compared to control. Among the aggregates, in macro-aggregate fraction (250–500
μm and 500–1000
μm size fraction) and in large macro-aggregate fraction (>2000
μm) maximum soil organic carbon concentration was recorded under NPK
+
FYM. The root mass of soybean was mostly (98%) confined to 15
cm soil depth. Combined application of NPK and FYM recorded significantly higher (
P
<
0.05) root length density and root mass density of soybean in the 0–15
cm soil layer at flowering stage over NPK (28 and 65%) and control (63 and 175%). The root length density of soybean was significantly negatively correlated with the penetration resistance (
r
=
0.98,
P
<
0.05). Application of FYM @ 4
Mg
ha
−1 with NPK significantly (
P
<
0.05) improved the biomass partitioning towards pod over NPK and control. The grain yield, water use efficiency and nitrogen use efficiency of soybean under NPK
+
FYM were significantly (
P
<
0.05) higher than NPK and control. The total above ground biomass and the leaf area index at R8 stage could account for respectively, 89 and 63% variation in grain yield of soybean. Therefore in every crop season, integrated use of farmyard manure at 4
Mg
ha
−1 and recommended dose of chemical fertilizers may be practised in Vertisols for improving soil physical environment and achieving higher soybean productivity through efficient utilization of water and nutrients.
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