Offset Temperature Research Articles

A 24.4 ppm/°C Voltage Mode Bandgap Reference With a 1.05V Supply

This brief proposes a sub-1V, voltage mode CMOS bandgap reference circuit. Conventionally, sub-1V references are obtained by converting PTAT and CTAT voltages to currents and summing them in the current domain. Such techniques have multiple operating points and cannot natively support applications that require PTAT currents in addition to a bandgap voltage. This brief presents a voltage mode reference circuit, which adds a PTAT voltage with a scaled version of a CTAT voltage all within the sub-1V domain. Compared to current mode bandgaps, summing in voltage domain enables reduction of one CTAT current mirror stage and a significant reduction in PTAT current mirror ratio resulting in a reduced number of error sources. In addition, this circuit also natively supports applications that require PTAT current. A novel, high-accuracy self-biasing technique has been adopted to minimize the systematic offset induced temperature coefficient. A prototype designed in 45nm TSMC CMOS technology for a nominal voltage of 500mV demonstrates 24.4ppm/°C temperature coefficient from -40°C to 125°C, 0.15% line regulation, and draws 7.2μ\textA from a 1.05V supply.

Improvement of melting and crystallisation properties of rambutan seed fat as cocoa butter improver by two‐stage fractionation technique

SummaryThe search for hard fats is increasing by the day due to their demand for industrial purposes. Rambutan seed fat (RSF) was fractionated prior to investigate the melting and crystallisation behaviours, triacylglycerols (TAGs), and morphology using different chromatographic and thermal techniques. The increasing trends were observed for high‐melting symmetrical monounsaturated TAGs such as 1,3‐distearoyl‐2‐oleoyl‐glycerol and 1‐palmitoyl‐3‐stearoyl‐2‐oleoyl‐glycerol in both solid fractions upon fractionation. The solid fractions (F1‐S) and (F2‐S) exhibited small peaks towards low melting area and big peaks towards high melting area with the offset temperatures of 35.29–48.75 °C and 43.58–52.70 °C with significantly higher enthalpies (93.49 and 105.13 J g−1) upon fractionation. F2‐S showed the densely packed microstructure compared to that of crude RSF and F1‐S. Based on the thermal behaviours as well as morphology of RSF fractions, cocoa butter improver could be prepared that has the potential to be utilised in chocolate manufacturing in tropical countries.

Offset analgesia identifies impaired endogenous pain modulation in pediatric chronic pain disorders.

Offset analgesia (OA), a psychophysical test of endogenous pain inhibition, is diminished in many adult chronic pain disorders but OA has not been investigated in youth with chronic pain disorders. This study assessed OA responses in 30 youth with chronic primary and secondary pain disorders and 32 healthy controls. The OA, control, and constant thermal tests were evoked with an individualized noxious heat stimulus of approximately 50/100 mm on a visual analogue scale followed by 1°C offset temperature. This study also examined the association of OA responses with 2 self-report measures of pain sensitivity, the Central Sensitization Inventory (CSI) and Pain Sensitivity Questionnaire. Patients exhibited diminished capacity to activate OA with a reduction in ΔeVASc of 53 ± 29% vs controls 74 ± 24% (P = 0.003) even after multivariate regression adjusting for age, sex, and body mass index. Patients also showed decreased ability to habituate to a constant noxious heat stimulus compared to controls (P = 0.021). Central Sensitization Inventory scores showed excellent predictive accuracy in differentiating patients from controls (area under the curve = 0.95; 95% CI: 0.91-0.99) and CSI score ≥30 was identified as an optimal cutoff value. Pain Sensitivity Questionnaire scores did not differentiate patients from controls nor correlate with OA. In this study, 60% of youth with chronic pain showed reduced capacity for endogenous pain inhibition.

Hall effect instruments, evolution, implications, and future prospects.

Since the revolution in solid state electronics, many innovative principles were investigated for a better and simpler design. Thus, Hall effect-based sensors and instruments gained importance. To employ this principle in several operating conditions and with different setups, several researchers contributed significantly over the decades, which ultimately led to the establishment of industries producing a wide range of Hall devices. The objective of this paper is to review the available configurations and current status of the Hall effect-based technologies. A detailed discussion is carried out on the various types of existing Hall-based devices, such as linear sensors, field-programmable sensors, switches, latches, speed and directional sensors, and vane sensors. The effect of materials and the influence of several undesired effects (such as offset voltage, temperature, noise, and drift) are also investigated. The compensation/reduction techniques are mentioned therein, and interested researchers are encouraged for the development of new techniques. This paper concludes with the discussion on the market scenario (such as electronics sector and automotive industry) and progression in current research on Hall devices while projecting some new research directions in this field.

Correction: Postvaccination Fever Response Rates in Children Derived Using the Fever Coach Mobile App: A Retrospective Observational Study.

[This corrects the article DOI: 10.2196/12223.].

New 20 GHz push–push common‐collector Colpitts VCO

A wide-band push–push common-collector Colpitts voltage-controlled oscillator (VCO) usingimpedance peaking network and gain enhancing technique is proposed in this work.The impedance peaking network is introduced to increase the coupling factor ofthe differential inductor in the inductorcapacitor (LC) tank without sacrificing the quality factor. The impedancepeaking technique could guarantee the push–push VCO unconditionally oscillatingin a differential mode without degrading the phase noise performance. The gainenhancing technique employs an LC resonator in series with the emitterdegeneration resistor in the common-collector amplifier in the VCO core toimprove the VCO oscillating amplitude and then improve the phase noiseperformance. The proposed VCO oscillates at around 20 GHz with >10.5%frequency tuning range from 18.9 to 21.4 GHz across temperature from −40 to125°C. The measured phase noise is lower than −107 dBc/Hz at 1 MHz offset acrossthe entire working temperature (−40 125°C). The whole VCO dissipates 45 mA under3.3 V power supply, and the typical figure of merit is around −177.92.

Effect of Co/Cu partial replacement on fundamental features of Y-123 ceramics

This study is liable for the effect of sample production processes including the standard solid-state reaction (SSR) and classical sol–gel (SG) preparation methods on the fundamental characteristic features, namely electrical, superconducting, crystal structure quality, crystallinity, morphological, strength quality of grain boundary couplings, and interaction between the grains of YBa2Cu3−xCoxO7−δ (Y-123) advanced ceramic compounds within the weight ratio intervals x = 0–20%. The main heat treatments are exerted at two main steps: (I) annealing at 950 °C for 24 h in air medium conditions and (II) annealing at 500 °C during 5 h under the oxygen annealing ambient. The standard measurement methods such as powder X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, temperature-dependent electrical resistance, and Vickers hardness measurements are performed for the characterization of materials. It is found that the samples prepared at SSR route present much more superior characteristic features as compared to those fabricated at SG technique, being one of the most striking points deduced this work. In more detail, every material prepared crystallizes in the orthorhombic symmetry and exhibits the superconducting nature but considerable decrement in the critical transition temperatures. The onset and offset transition temperatures are noted to decrease regularly from 92.96 K (92.28 K) to 90.20 K (83.59 K); and 90.05 K (90.03 K) to 45.97 K (30.49 K) for the materials prepared by the SSR (SG) route. Similarly, the variation in the lattice cell and average grain size parameters confirm that the Co/Cu substitution damages Y-123 superconducting phase. Additionally, the Co/Cu partial replacement mechanism leads to increase significantly the Vickers hardness results. To sum up, the Co/Cu partial substitution (produced by either SSR or SG method) is plowed to improve the fundamental characteristic features for new, novel, and feasible market application areas of Y-123 cuprate ceramics in the universe economy.

Calibration of a W/Re thermocouple using Pd-C, Pt-C and Ru-C eutectic cells at NIM

In the paper, an in-house W/Re thermocouple was calibrated at the eutectic fixed points of Pd-C (1492 °C), Pt-C (1738 °C) and Ru-C (1953 °C). To correct the temperature error caused by the thermal conduction of the thermocouple sheath, a linear extrapolation method was developed to determine the emf of the thermocouple based on the melting and freezing values at the eutectic fixed points realized with different offset furnace temperatures. In a simpler approach, the average of the melting and freezing values was also used. The results showed that the temperatures corresponding to the emfs derived from the linear extrapolation and the average method agreed (1–2) °C with the standard reference values of type-C thermocouple in the temperature range studied.

Study of laser surface texturing of 6061 aluminium with thermal assistance

Laser surface texturing (LST) on 6061 aluminium with thermal assistance was carried out. The mechanisms of LST under various offset temperatures were expounded and clarified. The experimental results demonstrate that the offset temperature during laser processing has a significant influence on the formation of micro-features, evolution of oxidation reactions, surface morphology, resolidification characteristics and surface components. With the aid of an offset temperature, the interaction between a laser and the target materials can be significantly enhanced; thus, physical ablation and modification for LST can be achieved effectively. The ablation efficiency with an offset temperature of 300 °C can be up to approximately four times higher than that at room temperature, i.e. 25 °C. Moreover, the efficiency of surface texturing to realize a darkening effect on the sample surface with a temperature of 300 °C (200 µm s−1) is approximately four times faster than that with a temperature of 25 °C (50 µm s−1). Furthermore, the ablation threshold on 6061 aluminium with respect to different offset temperatures was determined. The derived result suggests that compared to normal LST, the ablation threshold can be reduced during thermal-assisted laser texturing.

Study of a Far Infrared Cavity around an AGB Star under Iras Survey at Galactic Latitude -1.6°

In this paper, we discuss about the physical properties of the dusty environment around the AGB star located at R.A. (J2000) = 06h 42m 02s and Dec (J2000) = 00° 53’ 00”, in the far infrared (60 and 100μm) IRAS maps. A cavity like structure (major diameter ∼ 2.5 pc & minor diameter ∼0.9 pc) is found to lie at R.A. (J2000) = 06h 41m 43.03s and DEC (J2000) = 01° 09’ 22.8”, located at a distance ∼ 405 pc from the star. By using contour map diagram, we studied the distribution of flux density, dust color temperature, dust mass and outflow mass in the cavity. The dust color temperature is found to lie in the range 21.4K to 21.9 K which shows the cavity is isolated and independently evolved. Such a low offset temperature variation shows that the star is stable and its life is long. Dust particles are less interacting and mean free path is large. The cavity may be in thermally pulsating phase. Product of dust color temperature and visual extinction is found to be less than one. A possible explanation of the results will be discussed.

Synthesis and characterization of hypoeutectic Al-Mg nano powder produced by electrical explosion method

Hypoeutectic composition of Al-Mg alloy binary system was established as a stabilized composition for production of Al-Mg alloy nano powders for fabrication of solid propellant. Nano powder of hypoeutectic Al-Mg alloy was prepared by high voltage Electrical Wire Explosion Process (EEW) under inert Argon and Helium gas environment with chamber pressure of 25 kPa and 50 kPa. The thin wires for explosion were prepared by Electrical Discharge Machining (EDM) process from Al-Mg alloy cast. XRD analysis of powder produced and alloy cast was performed to compare the phases present. Scanning Electron Microscope (SEM) images were taken for studying the shape and structure of the nano powder particles and Energy Dispersive Analysis of x-rays (EDX) was performed for affirming elemental composition of alloy powder. Morphological characteristics of nano powders were analyzed by Transmission Electron Microscope (TEM) images and the particle diameter was found ranging from10 nm to 90 nm. Highly magnified TEM images were obtained to analyze the formation of various phases in the powder. Thermo-Gravimetric Analysis and Differential Scanning Calorimetry (TGA-DSC) measurements were made to substantiate the low melting nature of Al-Mg alloys predicted by Al-Mg binary phase diagram with an offset temperature of melting 460 °C, which is much closer to the eutectic melting point (450 °C) of Al-Mg binary metal alloy. With the improved ductility of hypoeutectic alloys enabling better machinability to produce thin wires than eutectic composition, the results suggests hypoeutectic nano powders can be used as replacement for nano aluminium as energetic element in solid propellants.

Single-year thermal regime and inferred permafrost occurrence in the upper Ganglass catchment of the cold-arid Himalaya, Ladakh, India

Cold-arid regions of the trans-Himalaya in the Indian Himalayan Region (IHR) is suspected to have a significant area of permafrost. However, information on the ground thermal regime of these permafrost areas is so far not available. This study bridge this knowledge gap by analysing the sub-surface thermal regime of selected sites in the Ganglass catchment, Ladakh range. Near surface ground temperature data recorded during September 2016 to August 2017 using 24-miniature temperature data loggers distributed across 12 plots and covering an elevation range of 4700–5612 m a.s.l. are used in this study. Permafrost characteristics including plausible ranges of thermal offset, active-layer thickness and mean annual ground temperature at 10 m depth were estimated by driving a one-dimensional heat conduction model. Two statistical models were used to map first order estimates of permafrost area in this 15.4 km2 catchment. Study suggest permafrost occurrence at all sites above 4900 m a.s.l. with active-layer thickness ranging from 0.1 to 4.2 m and the mean annual ground surface temperature ranging from between −10.0 and −0.85 °C for these sites. MAAT at these sites range from −4.1 to −8.9 °C and the surface offsets vary from −1.1 to 3.9 °C. Estimated thermal offset range from −0.9 to 0 °C. Both statistical models show comparable results and suggest 95% mean permafrost cover in the catchment above 4727 m a.s.l. These results strongly indicate existence of significant permafrost areas across the high elevations of the cold-arid regions of IHR. So far, permafrost processes are not considered for assessing present and future estimates of water and regional climate and as a causative factor for disasters like debris flows and landslides in the region. This study highlight the need for greater research efforts on Himalayan permafrost to have a comprehensive understanding of Himalayan cryosphere.

Study on processing characteristics and mechanisms of thermally assisted laser materials processing

Nanosecond pulsed lasers have been widely applied to interact with and characterize many different materials, and industrial users are exploring more avenues for various application processes. For the purpose of achieving broader application, the current challenge is to achieve a high processing efficiency for laser materials processing. In this study, thermally assisted laser materials processing (TALMP), which introduces heat from an external source to increase the workpiece material's temperature and make it easier to carry out ablation or modification, was developed and investigated. Moreover, to investigate the materials processing characteristics and mechanisms of TALMP, practical applications using TALMP, including surface ablation on WC-Co, and surface polishing on additive manufactured Ti-6Al-4V, were carried out. The results showed that TALMP can be successfully applied to various materials by different laser materials processing applications. Due to the workpiece material's high temperature and heat content, the coupling between laser and target materials can be enhanced; thus, physical ablation and modification for laser surface ablation can be achieved effectively. However, with a high offset temperature, a little decrease of ablation accuracy and quality could occur, and a two-step approach is proposed to eliminate this unwanted effect. Moreover, this strategy is proven to be able to achieve the desired surface ablation with high efficiency and high-quality surfaces. For thermally assisted surface polishing, due to higher temperature field with long duration, a smoother and flatter polished surface can be obtained more easily. The experimental results proved the superiority and versatility of TALMP.

Effect of K Substitutions on Structural and Superconducting Properties in Bi1.6Pb0.4Sr2-xKxCa2Cu3O10+ Compounds

Abstract: Effect of K substitutions on structural and superconducting properties in Bi-Pb-Sr-Ca-Cu-O (BPSCCO) system has been investigated. Bulk Bi1.6Pb0.4Sr2-xKxCa2Cu3O10+d (where x = 0.00; 0.04; 0.08 and 0.1) samples were fabricated by using the solid-state reaction method. Structural properties of the samples were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) measurement. All samples showed co-existence of Bi-2223 and Bi-2212 superconducting phases. Interestingly, a formation of the Bi-2223 was decelerated and that of the Bi-2212 was accelerated with increasing K content (x). Superconducting properties of the samples were characterized by using temperature dependences of resistance and field dependences of magnetization data. Both onset and offset transition temperatures were found to decrease, those were correlated to the decreases in residual resistance ratio (RRR). The 65 K magnetization curves of K- substituted samples were enlarged in comparison with that of the pure one. Enlargements of the magnetization curves were possibly attributed to the appearance of additional point-like defects generated by substitutions of K into Sr site.
 Keywords: BPSCCO, substitutions, flux pinning, defects.

Mean Flow and Turbulence of a Heated Supersonic Jet with Temperature Nonuniformity

An experimental investigation of the mean flow and turbulence characteristics of two Mach 1.5 heated jets (one with a uniform temperature profile and another with an offset nonuniform temperature profile) is presented. The thermal nonuniformity is generated by introducing a matched static pressure stream of low-temperature air into the subsonic, converging section of a round contoured supersonic nozzle. The secondary plume, which is offset radially from the geometric centerline of the round jet nozzle, produces a jet with an altered velocity profile, modifying the turbulence throughout the jet plume. On the side of the jet where the cooler stream is introduced, the near-nozzle peak velocity is reduced to 83% of the heated jet exit velocity, which is associated with a reduction in the measured peak turbulent stress levels in the region between three to six jet diameters from the nozzle exit. Several aspects of the mean flow and turbulence structure in the developing plume with temperature nonuniformity are similar to those seen in multistream coannular round jets with offset nozzles, indicating that alternative engineering approaches may be available for generating the characteristics of offset plumes desirable for jet noise reduction.

A chip-level oven-controlled system used to improve accuracy of silicon piezoresistive pressure sensor

High precision is an important indicator for the silicon piezoresistive pressure sensor, which is deeply affected by the ambient temperature. This paper presented a chip-level oven-controlled system to operate the silicon piezoresistive pressure sensor at a constant temperature. However, the changes in ambient temperature still affect the temperature of the silicon piezoresistive pressure sensor due to the non-coplanar temperature control and the direct heat transfer between the piezoresistance on the surface of the pressure sensor and the environment. In order to decrease the effects and further improve the accuracy of the silicon piezoresistive sensor, a compensation function was introduced in the designed system. In addition, the oven-controlled structure fabricated by the MEMS process and the silicon piezoresistive pressure sensor were implemented at the chip level, which further reduced power consumption. The feasibility of the design was verified by the results of the thermodynamic model and COMSOL Multiphysics simulation analysis. Test results showed that when the pressure ranged from 100 hPa to 1100 hPa, the designed system performed a maximum measurement error no more than ±0.2 hPa from −45 °C to 45 °C. After compensation, the accuracy, sensitivity temperature coefficient, offset temperature coefficient of the silicon piezoresistive pressure sensor can reach 0.02% FS, 1.081 × 10−5/°C, 2.22 × 10−4% FS/°C respectively.

A silicon Hall sensor SoC for current sensors

In this paper we present a System on Chip (SoC) that implements a Hall Effect Sensor along with its readout circuits and calibration support. The sensor is designed for use in Hall effect based current sensors. The SoC was implemented in 0.18u CMOS technology and integrates Hall sense elements, preamplifiers as well as a delta sigma ADC, a DAC and a digital calibration. The SoC achieves 11 V/T gain and 0.76% RMS accuracy over a range of ±300 mT and 30 kHz signal bandwidth. The SoC integrates a digital correction unit that implements a polynomial computation algorithm for calibrating out the current sensor’s magnetic core induced nonlinearities. Offset temperature drift of the sensor is 6.81μT per degrees over −40 °C to 85 °C range. A current sensor is built using the SoC. It can measure currents from −10 A to 10 A and achieve 1.67% RMS measurement accuracy.

Water quality improvements offset the climatic debt for stream macroinvertebrates over twenty years

Many species are accumulating climatic debt as they fail to keep pace with increasing global temperatures. In theory, concomitant decreases in other stressors (e.g. pollution, fragmentation) could offset some warming effects, paying climatic debt with accrued environmental credit. This process may be occurring in many western European rivers. We fit a Markov chain model to ~20,000 macroinvertebrate samples from England and Wales, and demonstrate that despite large temperature increases 1991–2011, macroinvertebrate communities remained close to their predicted equilibrium with environmental conditions. Using a novel analysis of multiple stressors, an accumulated climatic debt of 0.64 (±0.13 standard error) °C of warming was paid by a water-quality credit equivalent to 0.89 (±0.04)°C of cooling. Although there is finite scope for mitigating additional climate warming in this way, water quality improvements appear to have offset recent temperature increases, and the concept of environmental credit may be a useful tool for communicating climate offsetting.

Postvaccination Fever Response Rates in Children Derived Using the Fever Coach Mobile App: A Retrospective Observational Study.

BackgroundPostvaccination fever is a mild adverse event that naturally improves without complications, but is highly prevalent and can be accompanied by febrile convulsions in some cases. These adverse effects may cause parents to delay or avoid vaccinating their children.ObjectiveThis study aimed to identify postvaccination fever patterns and the ability of antipyretics to affect changes in these patterns from data collected from a mobile app named Fever Coach.MethodsData provided by parents of feverish children derived from a mobile app, Fever Coach, were used to identify postvaccination fever patterns according to vaccinations and the use of antipyretic drugs. We selected single vaccination records that contained five or more body temperature readings performed within 48 hours of vaccination, and we analyzed postvaccination fever onset, offset, duration, and maximum body temperature. Through observing the postvaccination fever response to vaccination, we identified the effects of antipyretic drugs on postvaccination fever onset, offset, and duration times; the extent of fever; and the rate of decline. We also performed logistic regression analysis to determine demographic variables (age, weight, and sex) involved in relatively high fevers (body temperature ≥39°C).ResultsThe total number of Fever Coach users was 25,037, with 3834 users having entered single vaccination records, including 4448 vaccinations and 55,783 body temperature records. Most records were obtained from children receiving the following vaccinations: pneumococcus (n=2069); Japanese encephalitis (n=911); influenza (n=669); diphtheria, tetanus, and pertussis (n=403); and hepatitis A (n=252). According to the 4448 vaccination records, 3427 (77.05%) children had taken antipyretic drugs, and 3238 (89.15%) children took antibiotics at body temperatures above 38°C. The number of children taking antipyretics at a body temperature of 38°C was more than four times that of those taking antipyretics at 37.9°C (307 vs 67 cases). The number of instances in which this temperature threshold was reached was more than four times greater than the number when the temperature was 37.9°C. A comparative analysis of antipyretic and nonantipyretic cases showed there was no difference in onset time; however, offset and duration times were significantly shorter in nonantipyretic cases than in antipyretic cases (P<.001). In nonantipyretic cases, offset times and duration times were 9.9 and 10.1 hours shorter, respectively, than in antipyretic cases. Body temperatures also decreased faster in nonantipyretic cases. Influenza vaccine-associated fevers lasted relatively longer, whereas pneumococcus vaccine-associated fevers were relatively short-lived.ConclusionsThese findings suggest that postvaccination fever has its own fever pattern, which is dependent on vaccine type and the presence of antipyretic drugs, and that postvaccination temperature monitoring may ease fever phobia and reduce the unnecessary use of antipyretics in medical care.

Degradation in fundamental characteristic features of Bi-2212 superconducting ceramic material with Sr/Ti partial substitution

The present work investigates the vital differentiations in some basic characteristic properties including the crystallinity quality, flux pinning mechanism, superconducting, dc electrical features, grain boundary coupling problems and strength of connection between the superconducting grains in the poly-crystallized Bi2.1Sr2.0−xTixCa1.1Cu2.0Oy cuprate ceramic materials with the partial aliovalent substitution of Sr2+ impurities for the Ti4+ foreign additives in the crystal system. All the materials are prepared by the standard solid-state reaction method, and the characterization of samples produced is thoroughly performed by the typical experimental measurements such as dc electrical resistivity over the temperature, critical current density and powder X-ray diffraction investigations. It is obvious that all characteristic properties tend to diminish constantly with the augmentation of the aliovalent Sr/Ti partial replacement level, and in case of x = 0.10 they reach the global minimum values. To illustrate, the low Bi-2212 superconducting phase diverges from the stabilization because of new induced permanent crystal structure (crystallinity) problems such as the voids, porosity, defects, texturing, cracks, grain boundary coupling problems, grain alignment distributions, stress raisers, omnipresent flaws and crack initiation sites in the crystal system. Besides, the presence of Ti impurities leads to the formation of new impurity phases related to very low superconducting and characteristic TiO2 phase, being favored by either the decrement of c lattice cell parameter or increment of a-axis length. The similar findings are observed in the temperature dependent electrical resistivity measurements. Namely, the electrical resistivities at the normal state are found to increase dramatically from about 74.75–180.47 mΩcm whereas the offset and onset critical temperature values are recorded to diminish from 82.11 K (for the pure sample) to 50.52 K (for the sample prepared with x = 0.10 substitution level) and 84.03–75.14 K, respectively, with the enhancement in the substitution level. Likewise, the Sr/Ti partial replacement affects negatively not only the thermal fluxon motions of correlated two-dimensional pancake vortices but also the ability and strength of vortex lattice period, elasticity, effective and active energy barriers for the flux pinning centers in the Bi-2212 superconducting crystal lattice. In this respect, the Sr/Ti partial substitution mechanism is ploughed to improve the fundamental characteristic features.