Hill Type Research Articles

Advanced morphological analysis of siloxane-hydrogel contact lenses.

The purpose of this work is to provide a better understanding of three-dimensional (3-D) surface texture of siloxane-hydrogel contact lenses (CLs) using atomic force microscopy (AFM) and stereometric analysis. The 3-D surface texture characterization of unworn/worn siloxane-hydrogel CLs made of Filcon V (I FDA group) was performed with stereometric analysis. The atomic force microscopy (AFM) measurements of surface roughness and micromorphology of CLs were made using a Nanoscope V MultiMode (Bruker) in intermittent-contact mode, in air, on square areas of 5 × 5μm. Stereometric study of 3-D surface texture was made according with ISO 25178-2:2012 for CLrins (taken from the blister and rinsed with deionized water); CLss (preserved for 12 hr in saline solution and rinsed with deionized water); CLworn-smooth (worn for 8hr and presenting the smooth type morphology), and CLworn-sharp (worn for 8hr and presenting the sharp-type morphology). The 3-D surface texture of siloxane-hydrogel CLs was found to have specific morphological characteristics. Statistical parameters revealed local geometrical and morphological spatial structures at nanometer scale attributed to the specific interactions at the CLs surface. Before wear, the surface micromorphology of Filcon V CLs is regular with uniformly distributed microasperities and relatively small heights (Sq=0.6nm). After 12 hr in saline, it is found that the micromorphology changes relatively easily, but retaining the main morphological characteristics (Sq=1.2nm). After 8hr of wear, there are two typical micromorphologies: smooth type, characterized by gutter structures and isolated microasperities (Sq=2.5nm), while the sharp type has an appearance with compactly arranged microasperities of hill type flanked by compactly arranged microregions of valley type (Sq=2.2nm). Surface statistical parameters allow manufacturers in developing the next generation of CLs with improved surface texture while improving biocompatibility and minimizing the impact of the material on corneal physiology. Furthermore, the micro-elastohydrodynamic lubrication due to surface texture at a nanometer scale between the back surface of the CL with the corneal surface and the front surface of the CL with the under-surface of the eyelid can be deeper and more nuanced to understand in light of modern tribological theories.

Dynamic instability of trapezoidal composite plates under non-uniform compression using moving kriging based meshfree method

Meshfree formulation based on the element free Galerkin method (EFGM) in conjunction with moving kriging (MK) shape function is employed to investigate buckling and parametric instability behaviour of shear deformable isotropic and laminated composite trapezoidal plates subjected to different types of non-uniform periodic edge compressive loads. Hamilton’s principle is used to derive the governing equations, which are transformed into the discretized form using the EFG method. The actual pre-buckling stresses are determined from static analysis to evaluate the accurate buckling loads of isotropic and laminated composite trapezoidal plates under non-uniform edge compression. The ordinary differential equations of Mathieu–Hill type are solved using Bolotin’s method to determine regions of dynamic instability. The accuracy of the present formulation is examined first by comparing results with those available in the literature. Thereafter, the influence of geometric parameters, lamination scheme, boundary conditions, static pre-load, and various types of non-uniform edge compression on the critical buckling loads and dynamic instability behaviour of both isotropic and laminated composite trapezoidal plate is investigated. The new results on dynamic stability behaviour of trapezoidal plates under non-uniform edge loads are presented for the first time, which may serve as benchmark results for future research. Furthermore, the time history response and corresponding phase plots are also presented for a better understanding of the dynamic behaviour of the trapezoidal plates.

The medial tangent of the proximal tibia is a suitable extra-articular landmark in determining the tibial anteroposterior axis

BackgroundTibial rotational alignment in total knee arthroplasty (TKA) is generally determined based on intra-articular structure, and can be difficult to ascertain in some cases. The aim of this study was to investigate whether the medial tangent angle of the tibia (MTAT) could be useful in determining the anteroposterior axis of the tibia.MethodsThis study was performed on 103 lower limbs in 53 patients who underwent primary total hip arthroplasty. The selection criteria for our study were based on the assumption that knees in patients undergoing THA exhibit fewer degenerative changes than knees in patients undergoing TKA. Using computed tomography images, the MTAT, comprising the medial tangent of the proximal tibia and the anteroposterior (AP) axis of the tibia, was measured on three horizontal planes: at the distal edge of the tibial tubercle (A), at 5 cm distally (B), and at 10 cm further distally (C). The tibial medial surface was grouped into three classes according to shape: valley type, flat type, and hill type. The percentage at which these shapes were observed in each group was also calculated. Measurement reliability was calculated using the intraclass correlation coefficient.ResultsThe angles were 45.2° (interquartile range: IR 43.0–47.7) at A, 42.7° (IR 38.7–45.9) at B, and 42.4° (IR 38.2–45.9) at C. Intra-rater reliability and inter-rater reliability was 0.982 and 0.974 at A, 0.810 and 0.411 at B, and 0.940 and 0.811 at C, respectively. Regarding the tibial medial surface, the valley type was observed in all cases at A, and the hill type was observed in the highest percentage of cases at B and C.ConclusionsThe MTAT was approximately 45° at level A, and reproducibility was the highest among the three groups. The two points forming the valley on the tibial medial surface were bony ridges. Therefore, the medial tangent of the tibia at level A could be easily determined. Because the distal edge of the tibial tubercle exists at the surgical area and the extra-articular area, it can be a suitable intraoperative, extra-articular landmark in determining the tibial AP axis, even for revision TKA.

Neuromechanics and Energetics of Walking With an Ankle Exoskeleton Using Neuromuscular-Model Based Control: A Parameter Study.

Powered ankle exoskeletons that apply assistive torques with optimized timing and magnitude can reduce metabolic cost by ∼10% compared to normal walking. However, finding individualized optimal control parameters is time consuming and must be done independently for different walking modes (e.g., speeds, slopes). Thus, there is a need for exoskeleton controllers that are capable of continuously adapting torque assistance in concert with changing locomotor demands. One option is to use a biologically inspired, model-based control scheme that can capture the adaptive behavior of the human plantarflexors during natural gait. Here, based on previously demonstrated success in a powered ankle-foot prosthesis, we developed an ankle exoskeleton controller that uses a neuromuscular model (NMM) comprised of a Hill type musculotendon driven by a simple positive force feedback reflex loop. To examine the effects of NMM reflex parameter settings on (i) ankle exoskeleton mechanical performance and (ii) users’ physiological response, we recruited nine healthy, young adults to walk on a treadmill at a fixed speed of 1.25 m/s while donning bilateral tethered robotic ankle exoskeletons. To quantify exoskeleton mechanics, we measured exoskeleton torque and power output across a range of NMM controller Gain (0.8–2.0) and Delay (10–40 ms) settings, as well as a High Gain/High Delay (2.0/40 ms) combination. To quantify users’ physiological response, we compared joint kinematics and kinetics, ankle muscle electromyography and metabolic rate between powered and unpowered/zero-torque conditions. Increasing NMM controller reflex Gain caused increases in average ankle exoskeleton torque and net power output, while increasing NMM controller reflex Delay caused a decrease in net ankle exoskeleton power output. Despite systematic reduction in users’ average biological ankle moment with exoskeleton mechanical assistance, we found no NMM controller Gain or Delay settings that yielded changes in metabolic rate. Post hoc analyses revealed weak association at best between exoskeleton and biological mechanics and changes in users’ metabolic rate. Instead, changes in users’ summed ankle joint muscle activity with powered assistance correlated with changes in their metabolic energy use, highlighting the potential to utilize muscle electromyography as a target for on-line optimization in next generation adaptive exoskeleton controllers.

Lyapunov–Perron Transformation for Quasi-Periodic Systems and Its Applications

Abstract This paper depicts the application of symbolically computed Lyapunov–Perron (L–P) transformation to solve linear and nonlinear quasi-periodic systems. The L–P transformation converts a linear quasi-periodic system into a time-invariant one. State augmentation and the method of normal forms are used to compute the L–P transformation analytically. The state augmentation approach converts a linear quasi-periodic system into a nonlinear time-invariant system as the quasi-periodic parametric excitation terms are replaced by “fictitious” states. This nonlinear system can be reduced to a linear system via normal forms in the absence of resonances. In this process, one obtains near identity transformation that contains fictitious states. Once the quasi-periodic terms replace the fictitious states they represent, the near identity transformation is converted to the L–P transformation. The L–P transformation can be used to solve linear quasi-periodic systems with external excitation and nonlinear quasi-periodic systems. Two examples are included in this work, a commutative quasi-periodic system and a non-commutative Mathieu–Hill type quasi-periodic system. The results obtained via the L–P transformation approach match very well with the numerical integration and analytical results.

Critical Comparison of MaxCal and Other Stochastic Modeling Approaches in Analysis of Gene Networks.

Learning the underlying details of a gene network with feedback is critical in designing new synthetic circuits. Yet, quantitative characterization of these circuits remains limited. This is due to the fact that experiments can only measure partial information from which the details of the circuit must be inferred. One potentially useful avenue is to harness hidden information from single-cell stochastic gene expression time trajectories measured for long periods of time—recorded at frequent intervals—over multiple cells. This raises the feasibility vs. accuracy dilemma while deciding between different models of mining these stochastic trajectories. We demonstrate that inference based on the Maximum Caliber (MaxCal) principle is the method of choice by critically evaluating its computational efficiency and accuracy against two other typical modeling approaches: (i) a detailed model (DM) with explicit consideration of multiple molecules including protein-promoter interaction, and (ii) a coarse-grain model (CGM) using Hill type functions to model feedback. MaxCal provides a reasonably accurate model while being significantly more computationally efficient than DM and CGM. Furthermore, MaxCal requires minimal assumptions since it is a top-down approach and allows systematic model improvement by including constraints of higher order, in contrast to traditional bottom-up approaches that require more parameters or ad hoc assumptions. Thus, based on efficiency, accuracy, and ability to build minimal models, we propose MaxCal as a superior alternative to traditional approaches (DM, CGM) when inferring underlying details of gene circuits with feedback from limited data.

Wind field characteristics over hilly and complex terrain in turbulent boundary layers

This study aims to provide a turbulent inlet generation method for Large Eddy Simulation with the consideration of cross-correlation modification, which can overcome the difficulties in completely meeting the specified turbulent characteristics, spectrum and time-correlation and integrate conveniently with the Spectral Element Method and Finite Volume Method. The proposed method is utilized for simulating turbulent boundary layer flow over two types of three-dimensional hills with different slopes, and then is validated by comparing with the wind tunnel tests. From the results, the proposed turbulent inlet generation method for Large Eddy Simulation can accurately predict the distribution of mean wind velocity and turbulence intensity over hilly terrain, and the Large Eddy Simulation with Spectral Element Method appears more efficient in competition than that with Finite Volume Method. Finally, the proposed method is employed to simulate turbulent boundary layer flow over real terrain in Changsha, China. The wind field characteristics of the target complex terrain are analyzed and discussed, which can be used for the fields of wind farm micro-siting over complex terrain in engineering practice.

Reservoir Characteristics and Genetic Mechanisms of the Mesozoic Granite Buried Hills in the Deep‐water of the Qiongdongnan Basin, Northern South China Sea

AbstractDue to its structure, rock and mineral composition, fluid and other factors, the granite Buried Hill Reservoir is highly heterogeneous with a complex longitudinal structure and a reservoir space made up of a combination of dissolution pores and fractures. This paper is based on current understanding of tectonic evolution in the northern part of the South China Sea, in conjunction with the seismic phase characteristics. It is determined that the meshed fault system was formed by three stages of movement ‐ tectonic compression orogeny during the Indochinese epoch, strike‐slip compression‐tension during the Yanshanian Period, early fracture extension activation during the Himalayan – which controlled the distribution of the Buried Hill Reservoir. Drilling revealed two types of buried hills, faulted anticline and fault horst, their longitudinal structure and the reservoir space type being significantly different. The mineral composition, reservoir space and diagenetic characteristics of the reservoir rocks and minerals were analyzed by lithogeochemistry, microsection and logging etc., it thus being determined that the Mesozoic rocks of the Songnan Low Uplift in the Qiongdongnan Basin are mainly composed of syenogranite, granodiorite, monzogranite, which is the material basis for the development of the Buried Hill Reservoir. The content of felsic and other brittle minerals is more than 70%, making it easy for it to be transformed into fractures. At the same time, the weathering resistance of granodiorite and monzogranite is weaker than that of syenogranite, which is easily weathered and destroyed, forming a thick sand gravel weathering zone. With increasing depth of burial, weathering and dissolution gradually weaken, the deep acidic fluid improving the reservoir property of internal fractures and expanding the vertical distribution range of the reservoirs. The research results lay a foundation for the exploration of Buried Hill in the deep‐water area of the Qiongdongnan Basin.

Periodic bouncing solutions for Hill's type sub-linear oscillators with obstacles

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The location of the femoral ACL footprint center is different depending on the Blumensaat's line morphology.

The purpose of this study was to evaluate the difference in the center point of the femoral ACL footprint according to the morphological variations of the Blumensaat's line. Fifty-nine non-paired human cadaver knees were used. The ACL was cut in the middle, and the femoral bone was cut at the most proximal point of the femoral notch. Digital images were evaluated using the Image J software. The periphery of the femoral ACL footprint was outlined and the center point was measured automatically. Following Iriuchishima's classification, the morphology of the Blumensaat's line was classified into straight and hill types (small and large hill types). The center of the femoral ACL footprint and hilltop placement were evaluated using the quadrant method. A quadrant grid was placed uniformly, irregardless of hill existence, and not including the articular cartilage. A correlation analysis was performed between the center point of the femoral ACL footprint and hilltop placement. The straight type consisted of 19 knees, and the hill type 40 knees (small hill type 13 knees and large hill type 27 knees). The center of the femoral ACL footprint (shallow-deep/high-low) in the straight and hill type knees was 33.7/47.6%, and 37.2/50.3%, respectively. In the hill type, the ACL footprint center was significantly more shallow when compared to the straight type. Significant correlation was observed between the center point of the femoral ACL footprint and hilltop placement of the Blumensaat's line. The center point of the femoral ACL footprint was significantly more shallow in the hill type knees when compared to the straight type. For clinical relevance, considering that the location of the femoral ACL footprint center is different depending on the Blumensaat's line morphology, to perform accurate ACL reconstruction, femoral ACL tunnel placement should be made based on Blumensaat's line morphological variations.

Identifying Characteristic and Anomalous Mantle From the Complex Relationship Between Abyssal Hill Roughness and Spreading Rates

AbstractThe dependence of abyssal hill roughness on mid‐ocean ridge (MOR) spreading rate is an important indicator for faulting and volcanism. I reanalyze this relationship using a global gravity‐based prediction of root‐mean‐square (RMS) heights, enabling dense sampling of RMS/spreading rate space and thus a far more detailed examination than possible with bathymetric data. RMS histograms are multimodal, indicating previously unrecognized complexity in roughness versus spreading rate that cannot be characterized by a single trend. Modal peaks are used to define four different types of abyssal hills, three of which can be associated with axial valley, transitional, and axial high MOR morphology. The most abundant type at any one spreading rate bin is used to define a “characteristic” trend that transitions abruptly from axial valley to axial high types across half rates of ~20 to 30 mm/yr. Abyssal hills outside this trend are associated geographically with anomalously “hot” and “cold” mantle regions.

Clinical feasibility of a new antireflux ablation therapy on gastroesophageal reflux disease (with video)

New mucosal resective and ablative endoscopic procedures based on gastric cardiac remodeling to prevent reflux have appeared. We aimed to evaluate the feasibility of a new ablative technique named antireflux ablation therapy (ARAT) for control of GERD in patients without hiatal hernia. Patients with proton pump inhibitor (PPI)-refractory GERD without hiatal hernia underwent ARAT between January 2016 and October 2019. Gastroesophageal Reflux Disease-Health-Related Quality of Life (GERD-HRQL), upper endoscopy, 24-hour pH monitoring, and PPI use were documented at 3, 6, 12, 24, and 36 months after ARAT. One hundred eight patients were included (61 men [56.5%]; median age, 36.5 years; range, 18-78 years). ARAT was performed on all patients. At the 36-month evaluation, 84 patients had completed the protocol. Median ARATtime was 35.5 minutes (range, 22-51 minutes), and median circumference ablation was 300° (range, 270°-320°). No major adverse events occurred, and 14 of 108 patients (12.9%) presented with stenosis that was responsive to balloon dilation (<5 sessions). At the 3-month evaluation, the acid exposure time (AET), DeMeester score, andGERD-HRQL score had decreased from 18.8% to 2.8% (P= .001), 42.5 to 9.1 (P= .001), and 36.5 to 10 (P=.02), respectively, and these values were maintained up to 36 months. Success (AET<4%) was achieved in 89% and72.2% at 3 and 36 months, respectively. Related factors at 36 months were as follows: pre-ARAT Hill typeII(odds ratio [OR], 3.212; 95% confidence interval [CI], 1.431-5.951; P= .033), post-ARAT 3-month Hill type I (OR, 4.101; 95% CI, 1.812-9.121; P= .042), and AET<4% at 3 months (OR, 5.512; 95% CI, 1.451-7.621; P= .021). ARAT is a feasible, safe, and effective therapy for early and mid-term treatment of GERD in patients without a sliding hiatal hernia. However, longer follow-up evaluations and randomized comparative studies are needed to clarify its real role. (Clinical trial registration number: NCT03548298.).

Evaluation of musculoskeletal modelling parameters of the shoulder complex during humeral abduction above 90°

Based on electromyographic data and force measurements within the shoulder joint, there is an indication that muscle and resulting joint reaction forces keep increasing over an abduction angle of 90°. In inverse dynamics models, no single parameter could be attributed to simulate this force behaviour accordingly. The aim of this work is to implement kinematic, kinetic and muscle model modifications to an existing model of the shoulder (AnyBody™) and assess their single and combined effects during abduction up to 140° humeral elevation. The kinematics and the EMG activity of 10 test subjects were measured during humeral abduction. Six modifications were implemented in the model: alternative wrapping of the virtual deltoid muscle elements, utilization of a three element Hill model, strength scaling, motion capture driven clavicle elevation/protraction, translation of the GH joint in dependency of the acting forces and an alteration of the scapula/clavicle rhythm. From the six modifications, 16 different combinations were considered. Parameter combinations with the Hill model changed the resultant GH joint reaction force and led to an increase in force during abduction of the humerus above 90°. Under the premise of muscle activities and forces within the GH joint rising after 90° of humeral abduction, we propose that the Hill type muscle model is a crucial parameter for accurately modelling the shoulder. Furthermore, the outcome of this study indicates that the Hill model induces the co-contraction of the muscles of the shoulder without the need of an additional stability criterion for an inverse dynamics approach.

Surface expression of microplate boundary kinematics: An isolated abyssal hill in the Mozambique Channel

In this contribution, high resolution multibeam swath bathymetry and PARASOUND sediment echosounder data are used to describe a region within the distal part of the central Mozambique Channel. The study area marks a transition from abyssal plain to abyssal hill type morphology within the sediment-rich Mozambique Fan and associated with a zone of extension in response to East African Rift System kinematics. Hosted within the abyssal hill lies an east-west orientated, elongate (80 km × 11 km) depression (relief of ca.175 m). Multibeam bathymetry and PARASOUND data show that the region surrounding the depression is variable in geomorphology including rugged irregular seafloor and sediment waves. Low gradient, smooth sea floor dominates the abyssal plain which returns several, distinct, sub-parallel sub bottom echoes. The flanks of the abyssal hill are marked by seafloor undulations likely evidence of bottom-current controlled geomorphology, and mass wasting deposits. The floor of the depression is characterised by hyperbolic echoes commonly associated with very rugged seafloor and basement outcrop with little sediment cover. The present-day geomorphology of the study area is the product of deep-seated ocean circulation and soft sediment deformation superimposed upon the antecedent geological framework, influenced by present-day kinematics of the East African Rift System. Faulting associated with these kinematics is manifest at the seafloor as the elongate steep-flanked depression; the result of an extensional regime expressed across the Mozambique channel from south-southwest to north-northeast. This contribution highlights the local, marine, ramification of a continental-scale largely terrestrial tectonic regime.

Morphology of the resident's ridge, and the cortical thickness in the lateral wall of the femoral intercondylar notch correlate with the morphological variations of the Blumensaat's line.

The purpose of this study was to reveal the morphological correlation between the lateral wall of femoral intercondylar notch and the Blumensaat's line. Forty-one non-paired human cadaveric knees were included in this study (23 female, 18 male: median age 83). Knees were resected, and 3 dimensional computed tomography (3D-CT) was performed. In the axial CT image, bony protrusion (resident's ridge) and cortical thickness in the lateral wall of the femoral intercondylar notch were detected. The length between the top of the ridge, or the most anterior, middle, and most posterior border of cortical thickness and posterior femoral condylar line was measured. Following Iriuchishima's classification, the morphology of the Blumensaat's line was classified into straight and hill types (small and large hill types). In the hill types, the length between the hilltop and the posterior border of the Blumensaat's line or the posterior border of the femoral condyle was evaluated. Statistical correlation was calculated between the top of the ridge location, cortical thickness location in the notch, and hilltop location. There were 7 straight type knees and 34 hill type knees (9 small hill type knees and 25 large hill type knees). Only the hill types of knees were evaluated. The top of the ridge, anterior margin, middle, and posterior border of cortical thickness in the lateral wall of the femoral intercondylar notch existed at 61.8 ± 4.6%, 58.3 ± 12.3%, 42.1 ± 7.9%, and 25.5 ± 5.4% from the posterior condylar line, respectively. The hilltop existed at 24.9 ± 5.9% and 30.7 ± 5.0%, from the posterior border of the Blumensaat's line and from the posterior border of the femoral condyle, respectively. Significant correlation was observed between resident's ridge top, cortical thickness location and hilltop location. In all cadaveric knees, cortical thickness was detected in the lateral wall of the femoral intercondylar notch. The resident's ridge and cortical thickness location had significant correlation with the hill location in the Blumensaat's line, indicating a continuation of the cortical bone from the posterior cortex of the femoral shaft via the hilltop of the Blumensaat's line to the cortical thickness in the lateral wall of the femoral intercondylar notch. For clinical relevance, hilltop location in the Blumensaat's line is a new bony landmark in anterior cruciate ligament surgery.

Chrysotile asbestos treated with phosphoric acid as an adsorbent for ammonia nitrogen

The purpose of this study was to find an alternative application for chrysotile asbestos, given that there is a complete structure of extraction and production of this class of serpentine minerals, but its use is banned for many applications. The idea was to obtain a compound that could immobilize phosphate by triggering a reaction between the magnesium oxide and hydroxide contained in the mineral, without causing phosphate leaching. To this end, chrysotile (Mg3SiO5(OH)4) was treated with phosphoric acid (H3PO4) in a molar ratio of 1:3 in an aqueous medium at 85 °C until the solvent evaporated, resulting in two different solid compounds, which were prepared in a similar manner. The first compound (cri/H3PO4 1:3)1, was obtained by rinsing and then heat-treating it at 150 °C for 6 h, while the second one, (cri/H3PO4 1:3)2, was rinsed after the heat treatment. Compound (cri/H3PO4 1:3)1 underwent partial leaching, while compound (cri/H3PO4 1:3)2 showed a mass increase of 48%, with the formation of crystalline magnesium pyrophosphate mixed with amorphous SiO2. The latter compound adsorbed N–NH3 at pH 10, following the pseudo-first-order model (activation energy = 8329 ± 1696 J mol−1). Equilibrium experiments, which were performed following Hill's sigmoidal type S2 isotherm model, indicated that the adsorption phenomenon was governed by two processes, i.e., complexation up to the inflection point (KH between 10.0 mg L−1 at 40 °C and 13.6 mg L−1 at 25 °C) followed by adsorption. The qmax varied from 18.0 to 19.6 mgN g−1 and the adsorbent was reusable, maintaining its initial adsorbent capacity during its first reuse. This material, which was tested on real effluents, presented a N–NH3 removal rate similar to that shown by the test solutions. The treatment of chrysotile with H3PO4 conducts it to a composite that adsorbs ammoniacal nitrogen at pH 10 and it is reusable maintaining the adsorption capacity.

Morphological Characterization and Diversity of T. Aman Rice Germplasm of Bangladesh

Fifty-four T. Aman rice landraces were studied for 11 morphological and yield contributing characters at Bangladesh Rice Research Institute during T. Aman 2016 season. The largest variation was observed for yield per hill with 53.6% CV, followed by 1000 grain weight (29.9), number of effective tillers per hill (22.8), culm diameter (18.8), leaf width (18.4), leaf length (18.1) and days to maturity (6.7) respectively. The longest leaf was recorded as 82.2 cm and that of culm diameter as 7.57 mm, grain length as 7.2 mm and LB ratio as 3.48. The shortest days to maturity (110 days) was observed in Kajal lata and plant height (86.6 cm) in Haijam. Indursail possessed the longest panicle (31.6 cm) and the highest yield per hill (24.3 g). Based on D2 values, all the germplasm were grouped into 15 clusters using Mahalonobis D2 statistic. The maximum numbers of germplasm (7) were grouped into the clusters IV with VI, whereas clusters III and XIII contained the minimum (1). The highest intra-cluster distance (1.0) was found in cluster II and the lowest (0.0) in clusters III and XIII, respectively. The inter-cluster D2 values ranged from 19.2 to 0.6 indicating wide range of diversity among the germplasm. Cluster XIII showed the highest leaf length (82.2 cm) and culm diameter (6.5 mm), cluster IX the highest effective tillers per hill (13), cluster II the lowest days to maturity (117), cluster XV the highest grain length (6.1 mm) and cluster I the highest grain LB ratio (2.97), while cluster VIII showed the highest yield per hill (22.0 g), panicle length (28.8 cm) and 1000 grain weight (25.2 g), respectively. Finally, the germplasm under clusters VIII may be selected for crossing with the germplasm from clusters XIII, IX, II, XV and I for developing high yielding varieties with improved panicle length, effective tillers per hill, growth duration and grain type.&#x0D; Bangladesh Rice j. 2018, 22(2): 13-22

Calculation of the number of peaks in The Gunung Sewu area using DEMNAS, focal maximum function and slope position classification method

Thousand Hills (Gunung Sewu) is a karst area in the southern Java island, stretches 85 km east to west covering around 1,300 km2 and formed by thousands of conical hills. This research aims to calculate the number of peaks in the Gunung Sewu area using focal maximum function and slope position classification. The data for the calculation was the Indonesian national DEM (DEMNAS). It was used in its original spatial resolution at 8.25 m, and the resampled version at 10 m and 16.5 m. The processing consists of detection of peaks, selection of top of hills, and evaluation. Twenty four combinations of window types and size and spatial resolution of DEMNAS were evaluated. The accuracy of the calculation was assessed using ten test areas with 1,576 hills digitized manually. The best function to detect the peaks is a rectangle type window with a width of three pixels with a spatial resolution at 8.25 m. Types of hills can be identified: conical and polygonal hills. The calculation found that there are 27,773 regional peaks, or hills, in the Thousand Hills area. The results were tested using a confusion matrix with overall accuracy is 86.2%.

Characterizing Interdisciplinarity of Nobel Laureates’ Key Publications

To know whether greater or smaller interdisciplinarity benefits high-quality scientific outputs, two indicators, the Brillouin’s (BI) and Hill-type (HI) indices, are applied to characterize interdisciplinarity of key publications of Nobel laureates from 2001 to 2010. Both BI and HI indicate that smaller interdisciplinarity benefits the creative works of these Nobel laureates. The results show high concordance between BI and HI, with high correlation (>0.8). Although all values, with BI < 1 and HI < 12, show that the interdisciplinarity is always small in the sample, the study also shows that interdisciplinary studies are more widely distributed in the field of physiology or medicine than that in physics.

Ferroelastic domain switching and R‐curve behavior in lead zirconate titanate (Zr/Ti = 52/48)‐based ferroelectric ceramics

AbstractIn this work, ferroelastic domain switching and R‐curve behavior in lead zirconate titanate (Nb/Ce co‐doped Pb(Zr0.52Ti0.48)O3, ab. PZT‐NC)‐based ferroelectric ceramics were investigated, using the indentation‐strength‐in‐bending (ISB) method. Firstly, Vickers indentation test examined the notable fracture anisotropy of PZT‐NC ceramics between the poling direction and its perpendicular direction, and the crack open displacement (COD) profiles in the two directions were also theoretically calculated from the indentation fracture mechanics. And then two kinds of ferroelastic domain switching modes (in‐plane and out‐of‐plane) were used for explaining such anisotropic propagation behavior of indentation cracks. The subsequent three‐point bending test illustrated the dependence of fracture strength on indentation load and the rising crack growth resistance curves (R‐curves) in two directions. The resulted R‐curves were fitted by the Hill's type Growth Function successfully, giving the reasonable values of crack extension exponential (n), plateau fracture toughness (Kmax), and initial fracture toughness (Kini). The in‐plane ferroelastic domain switching was identified as a more significant toughening mechanism for PZT‐NC ceramics than the out‐of‐plane switching due to more switchable domains.