Low Spring Research Articles

Chilling and Heat Accumulation of Fruit and Nut Trees and Flower Bud Vulnerability to Early Spring Low Temperatures in New Mexico: Meteorological Approach

Fruit and nut trees production is an important activity across the southwest United States and this production is greatly impacted by the local climate. Temperature is the main environmental factor influencing the growth and the productivity of the fruit and nut trees as it affects the trees’ physiology and the vulnerability of flower bud, flowers, and young fruit and nut to the low temperatures or spring frost. The objective of the present study is to estimate the chilling and heat accumulation of fruit and nut trees across New Mexico. Three study sites as Fabian Garcia, Los Lunas, and Farmington were considered and climate variables were collected at hourly time step. The Utah model and the Dynamic model were used to estimate the accumulated chilling while the Forcing model was used for the heat accumulation. The possible fruit and nut trees endodormancy and ecodormancy periods were also determined at the study sites. The results obtained chilling hours of 715 ± 86.60 h at Fabian Garcia, 729.53 ± 41.71 h at Los Lunas, and 828.95 ± 83.73 h at Farmington using the Utah model. The accumulated chill portions during trees’ endodormancy was 3.12 ± 3.05 CP at Fabian Garcia, 42.23 ± 5.08 CP at Los Lunas, and 56.14 ± 1.84 CP at Farmington. The accumulated heat was 8735.52 ± 1650.91 GDH at Fabian Garcia, 7695.43 ± 212.90 GDH at Los Lunas, and 5984.69 ± 2353.20 GDH at Farmington. The fruit and nut trees are at no risk of bud flowers vulnerability at Fabian Garcia while they are under high risk of bud flowers and or young fruit and nut vulnerability to low temperatures early spring as hourly temperature can still drop below 0 °C in April at the end of ecodormancy and flower blooming and young fruits and nuts development stage at Los Lunas and Farmington. Severe weather, especially frost conditions during winter and early spring, can be a significant threat to sustainable nut and fruit production in the northern New Mexico while high chilling requirement fruit and nut trees might not meet chill requirements in the southern New Mexico.

Multi-century tree-ring anatomical evidence reveals increasing frequency and magnitude of spring discharge and floods in eastern boreal Canada

Abstract In eastern boreal Canada, variability in river discharge is poorly understood at the multi-century scale due to short instrumental records. In recent decades, increased magnitude and frequency of spring floods have raised concerns about the potential effects of climate change on flood risk. Unlike tree-ring width, flood rings have a demonstrated dendrochronological utility for reconstructing high discharge in boreal environments. In this study, twelve chronologies of earlywood vessel cross-sectional area (a new hydrological proxy) and ring width were developed from riparian Fraxinus nigra trees periodically flooded in spring. These chronologies were used as predictors of Harricana River spring discharge, which was reconstructed for the period 1771–2016. The reconstruction captured 69% of the variance over a 102-year calibration period. The reconstruction indicates that the magnitude and frequency of spring high discharge has increased since the end of the Little Ice Age (1850–1870 CE) and since 1950. The change from a multi-decadal frequency in the late 19th century to a decadal and then interannual frequency in the late 20th century is associated with an increase in snow cover over much of central-eastern Canada. The association between the reconstructed spring discharge and spring atmospheric circulation indices NINO3.4, AMO, NAO may also have changed in these periods and further work is needed to assess the stability of these associations. The correlation between reconstructed and instrumental spring discharge at the regional scale, as well as the shared features in reconstructed discharge and other paleorecords from subarctic Quebec suggest a common hydrological signal across the study area and for the early 20th to 21st centuries. The unprecedently low and high spring discharge in recent decades compared to the historical natural variability of the last 250 years also suggests that the increase in flood frequency and magnitude originates from climate change.

Performance analysis of EBG bandstop filter using U: shaped meander type electrostatically actuated RF MEMS switch

Now a days, filters became essential component in many of the RF, satellites and wireless communication networks and system. The size and complexity of the system increases while dealing with multiple frequencies which employs a large number of filters. Hence, a single filter which can reconfigure at multiple frequencies is much more needed in the present scenario. In this paper, a reconfigurable band stop filter is designed by integrating RF MEMS switch. The proposed switch is modelled with U—shaped meanders which offers low spring constant of 1.54 N/m to reduce the Pull—in—voltage to 5.2 V. The suspended beam in the switch is actuated to reconfigure the frequency of the filter by varying the capacitance from upstate to down state. The reconfiguration in the frequency of filter is observed from 16.36 to 12.34 GHz showing good isolation of – 22.7 dB at 16.36 GHz and − 36.85 dB at 12.34 GHz. The analysis in the paper is carried out using COMSOL and HFSS FEM tools to understand the electromechanical and electromagnetic characteristics of both switch and Filter for Ku-band frequency application.

Caracterização hidrogeomorfométrica da microbacia do rio Gavião, Amazônia Ocidental, Brasil

As microbacias são unidades ideais para se obter as características da paisagem, e assim, planejar adequadamente a gestão dos recursos naturais em estabelecimentos agropecuários e áreas urbanas. O presente trabalho tem como objetivo realizar a caracterização da paisagem da microbacia do rio Gavião, localizada na Amazônia Ocidental, Brasil. Foram utilizados os softwares QGIS 2.10.1, Google Earth e TrackMaker Free, imagem altimétrica do satélite Alos (sensor Palsar) e equações disponíveis na literatura. A microbacia do rio Gavião tem área de 26,41 km2, perímetro de 32,41 km, forma alongada, altitudes de 207 a 300 m, predominância de relevos planos a ondulados, rede de drenagem de 21,25 km, padrão dendrítico de 3ª ordem, baixa densidade de nascentes, média densidade de drenagem, alto coeficiente de manutenção, canal principal muito reto e tempo de concentração de 2,74 h. Conclui-se que a microbacia tem potencial para o desenvolvimento de agropecuária, entretanto, é necessário adotar práticas de manejo conservacionista de solo e água, para mitigar os impactos da ação antrópica e garantir a conservação dos recursos hídricos.

Unfolding Textile-Based Pneumatic Actuators for Wearable Applications.

Textile based pneumatic actuators have recently seen increased development for use in wearable applications thanks to their high strength to weight ratio and range of achievable actuation modalities. However, the design of these textile-based actuators is typically an iterative process due to the complexity of predicting the soft and compliant behavior of the textiles. In this work we investigate the actuation mechanics of a range of physical prototypes of unfolding textile-based actuators to understand and develop an intuition for how the geometric parameters of the actuator affect the moment it generates, enabling more deterministic designs in the future. Under benchtop conditions the actuators were characterized at a range of actuator angles and pressures (0 - 136 kPa), and three distinct performance regimes were observed, which we define as Shearing, Creasing, and Flattening. During Flattening, the effects of both the length and radius of the actuator dominate with maximum moments in excess of 80 Nm being generated, while during Creasing the radius dominates with generated moments scaling with the cube of the radius. Low stiffness spring like behavior is observed in the Shearing regime, which occurs as the actuator approaches its unfolded angle. A piecewise analytical model was also developed and compared to the experimental results within each regime. Finally, a prototype actuator was also integrated into a shoulder assisting wearable robot, and on-body characterization of this robot was performed on five healthy individuals to observe the behavior of the actuators in a wearable application. Results from this characterization highlight that these actuators can generate useful on-body moments (10.74 Nm at 90° actuator angle) but that there are significant reductions compared to bench-top performance, in particular when mostly folded and at higher pressures.

Plant–soil interactions limit lifetime fitness outside a native plant’s geographic range margin

Plant species' distributions are often thought to overwhelmingly reflect their climatic niches. However, climate represents only a fraction of the n-dimensional environment to which plant populations adapt, and studies are increasingly uncovering strong effects of nonclimatic factors on species' distributions. We used a manipulative, factorial field experiment to quantify the effects of soil environment and precipitation (the putatively overriding climatic factor) on plant lifetime fitness outside the geographic range boundary of a native California annual plant. We grew plants outside the range edge in large mesocosms filled with soil from either within or outside the range, and plants were subjected to either a low (ambient) or high (supplemental) spring precipitation treatment. Soil environment had large effects on plant lifetime fitness that were similar in magnitude to the effects of precipitation. Moreover, mean fitness of plants grown with within-range soil in the low precipitation treatment approximated that of plants grown with beyond-range soil in the high precipitation treatment. The positive effects of within-range soil persisted in the second, wetter year of the experiment, though the magnitude of the soil effect was smaller than in the first, drier year. These results are the first we know of to quantify the effects of edaphic variation on plant lifetime fitness outside a geographic range limit and highlight the need to include factors other than climate in models of species' distributions.

MYB transcription factors drive evolutionary innovations in Arabidopsis fruit trichome patterning.

Both inter- and intra-specific diversity has been described for trichome patterning in fruits, which is presumably involved in plant adaptation. However, the mechanisms underlying this developmental trait have been hardly addressed. Here we examined natural populations of Arabidopsis (Arabidopsis thaliana) that develop trichomes in fruits and pedicels, phenotypes previously not reported in the Arabidopsis genus. Genetic analyses identified five loci, MALAMBRUNO 1-5 (MAU1-5), with MAU2, MAU3, and MAU5 showing strong epistatic interactions that are necessary and sufficient to display these traits. Functional characterization of these three loci revealed cis-regulatory mutations in TRICHOMELESS1 and TRIPTYCHON, as well as a structural mutation in GLABRA1. Therefore, the multiple mechanisms controlled by three MYB transcription factors of the core regulatory network for trichome patterning have jointly been modulated to trigger trichome development in fruits. Furthermore, analyses of worldwide accessions showed that these traits and mutations only occur in a highly differentiated relict lineage from the Iberian Peninsula. In addition, these traits and alleles were associated with low spring precipitation, which suggests that trichome development in fruits and pedicels might be involved in climatic adaptation. Thus, we show that the combination of synergistic mutations in a gene regulatory circuit has driven evolutionary innovations in fruit trichome patterning in Arabidopsis.

Stable cross-sectional dimensions for navigation channel in the estuary of Sangatta River, Indonesia

The objectives of this study are: 1) to capture the existing condition of the river channel in Sangatta River estuary, including the bathymetry of the river bed, and the cross-sectional dimensions of the river, 2) to design a stable navigation channel in Sangatta River estuary that allows less maintenance dredging and improves navigability of the channel during a critical condition when the water level is at the lowest, and 3) to test the effectiveness of the stable cross section in term of the availability of navigable depth. This research is divided into five stages, namely: 1) preparatory stage and preliminary survey, 2) main surveys, 3) hydrological and hydraulic analysis, 4) waterway design, and 5) dredging plan. The hydraulic analysis also includes determining the water level and depth profiles before and after dredging. HEC-RAS software is used to simulate, for each month, the water level and depth profiles in the channel at a critical condition when the sea water level is at low water spring (LWS) coincides with the river flow of 50% probability of occurrence, Q50. A stable channel for Sangatta River estuary is characterized with a bed slope, S = 0.00015, a flow depth, D = 3.6 m, a bed width, b = 76.3 m and a sidewall slope, m = 1.5. The simulation results show that the stable cross sections of the river provide sufficient water depth for navigation, even during the critical condition.

Species-specific growth-climate responses of Dahurian larch (Larix gmelinii) and Mongolian pine (Pinus sylvestris var. mongolica) in the Greater Khingan Range, northeast China

Responses of tree growth to climate are usually spatially heterogeneous. Besides regionally varying external environments, species specificity is a crucial factor in determining said spatial heterogeneity. A better understanding of this species specificity would improve our estimations of the warming effects on forests. In this study, we selected two widely-distributed boreal conifers, Dahurian larch (Larix gmelinii) and Mongolian pine (Pinus sylvestris var. mongolica), to compare their growth-climate responses, including long-term growth-climate correlations and short-term growth resilience to drought. We sampled 160 trees and 481 tree-ring cores from the two species in two pure and two mixed forests, located in the Greater Khingan Range, northeast China. We found that Dahurian larch was generally positively correlated with spring temperature and negatively correlated with summer temperature. In contrast, Mongolian pine was more sensitive to summer moisture. Our results suggest that the main climatic limitations were low spring temperatures for Dahurian larch and summer moisture deficits for Mongolian pine. Dahurian larch represented higher growth resistance to drought, while Mongolia pine represented higher recovery. Based on this, we inferred that Dahurian larch was more vulnerable to extreme droughts, while Mongolian pine was more vulnerable to frequent droughts. We also demonstrated the effects of forest type on growth-climate responses. The negative effects of summer temperatures on Mongolian pine seemed to be more significant in mixed forests. As warming continued, Mongolian pine in this area would suffer severer moisture deficits, especially when coexisting with Dahurian larch. Our results suggest that Dahurian larch gained an advantage in the competition with Mongolian pine during high moisture stress. Driven by the warming trends, the species specificity in growth response would ultimately promote the separation of the two species in distribution. This study will help improve our estimations of the warming effects on forests and develop more species-targeted forest management practices.

Hypogenic speleogenesis, late stage epigenic overprinting and condensation-corrosion in a complex cave system in relation to landscape evolution (Toirano, Liguria, Italy)

The Toirano karst system is located in the Ligurian Alps (north Italy), around 4.5 km inland from the coastline and carved in Middle Triassic dolostone. It comprises five cave levels over a 154 m altitudinal range, specifically Ulivo (340 m a.s.l.), Colombo (247 m a.s.l.), Upper Santa Lucia (215 m a.s.l.), Lower Santa Lucia (201 m a.s.l.) and Bàsura (186 m a.s.l.) caves. The system is active at lower altitudes, as testified by the thermal spring currently located at 70 m a.s.l. along the Varatella valley. Speleogenesis was attributed to the action of epigenic processes by other authors. However, the extraordinary geodiversity of the underground morphologies and deposits are at odds with this interpretation. Accordingly, this work investigates the genesis of the Toirano karst system, in relation to the landscape evolution of the surrounding area. A detailed morphological and mineralogical investigation of cave geoforms and deposits, together with the presence of the active low thermal sulphide spring on the Varatella valley and only ~100 m below the Bàsura Cave, sustain the hypothesis of a hypogene origin of the caves. This work shows that most of the caves formed close to the former water table (base) level, in turn determined by the mean sea level. Geochronological analyses, including U/Th (n = 13) and cosmogenic burial (n = 1) dating, together with an estimated incision rate of the Varatella valley of around 0.1 mm y−1, have allowed to assess the age of the highest cave (Ulivo) at around 2.7 Ma, Colombo at ~1.8 Ma, Upper Santa Lucia at ~1.5 Ma, Lower Santa Lucia ~1.3 Ma and Bàsura at ~1.2 Ma. Estimated palaeotemperature attained through isotope analyses and fluid inclusions on speleothems suggest that the temperature of rising waters was lower than 50 °C and possibly ranging between ~12 and ~20 °C, indicating that hydrothermal fluids were not the main driver of speleogenesis, at least in the late speleogenic phases. Additionally, sulphuric acid speleogenesis by-products were not identified. Accordingly, hypogenic speleogenesis occurred because of the action of low temperature CO2-rich rising fluids. A late stage of epigenic speleogenesis has been detected because of the clear evidences of condensation-corrosion morphologies, taking place since ~150 ka (possibly earlier) when caves were finally connected to the surface because of valley enlargement. Besides uncovering the genesis of the Toirano karst system, this study demonstrates that the combination of local geology, surface vs underground geomorphological observations, climate change vs landscape evolution evaluation and geochemical data is of key importance for interpreting subsurface land-shaping processes.

Conservation management of the green carpenter bee Xylocopa aerata (Hymenoptera: Apidae) through provision of artificial nesting substrate

AbstractThe green carpenter bee, Xylocopa aerata (Smith, 1851), has undergone a severe reduction in its distribution over the previous century, in part because of habitat loss and fragmentation and its dependency on old‐growth heathland habitats. In 2007, the last remaining South Australian population, on Kangaroo Island, was negatively affected by a shortage of nesting substrate as a consequence of a series of large, intense wildfires. In an attempt to prevent yet another extirpation of this species, we developed artificial nesting substrates (stalk nests and trunk nests) and placed them at various locations within the current range of the population. Monitoring showed that the bees readily used the alternative nesting substrate in sites where very little natural substrate was left. Reproductive activity was evaluated using X‐ray images of winter nests. Based on tunnel lengths and number of individuals, we conclude that conservation action has resulted in successful reproduction and that the number of nests used has increased each year. This is the first time that provision of nesting substrate is shown to substantially improve the breeding capacity of a threatened population of endemic bees in their natural habitat. However, reproduction in artificial substrate was significantly higher in 2016 than in 2017 and 2018. The most obvious reason for the decline in breeding was climatic – low spring and summer rain in the later years limited floral resources and hence reproduction. Global climate change is causing drier conditions and more frequent and intense fires, which are reducing the likelihood of survival of this species. This effect is demonstrated by the latest fire season which left only 5% of the bees' habitat intact on Kangaroo Island. Each large‐scale fire locally annihilates bees and destroys old growth nesting substrate which takes at least 35 years to recover, thus increasing the overall risk of extinction.

Conservation status of the southernmost reef of the Amazon Reef System: the Parcel de Manuel Luís

The Parcel de Manuel Luis (PML) is located at the southern end of the Amazon Reef System, which comprises the northernmost reef formations of the Brazilian biogeographical province. Its unique position and singular seascape make the PML an important stepping-stone for marine organisms between the Brazilian and Caribbean provinces. Yet, due to its distance from the shore, high tidal amplitude, and strong currents associated with a series of pinnacles exposed during low spring tides, the PML is one of the least studied reefs in the Western South Atlantic. Here, we integrated sessile benthic community data, fish assemblage surveys, and remote filming of fish interactions to establish the most complete community assessment of the PML reefs to date. In our surveys, we documented 78 sessile benthic taxa, with a taxonomic dominance of macroalgae (54 taxa), including two new occurrences of sponges for the North Brazilian Shelf, as well as four endemic species, such as the fire coral Millepora laboreli. The fish assemblage comprised 59 reef fish species, with biomass dominated mainly by large carnivorous species (e.g., groupers and snappers). Intra- and interspecific interactions were dominated by herbivorous fishes, particularly underpinned by grazing behavior and chasing by territorial species. The considerably high biomass and large-bodied species found in our surveys is rarely seen elsewhere in the Western South Atlantic, suggesting a low level of fishing compared to most other places, and only a few changes were observed in the fish assemblages since the first assessment made in 1998. We also highlight the usefulness of an integrated approach for continued assessment of Western South Atlantic reefs, particularly given emerging threats from mining and oil exploration, and the heavy traffic of commercial vessels in the region. Our findings support the PML as an area of critical conservation interest for reef systems, emphasizing the need for continued enforcement of this marine protected area and its integration in long-term plans of offshore oil and gas development projects.

A Low Spring Constant Piezoresistive Microcantilever for Biological Reagent Detection.

This paper introduces a piezoresistive microcantilever with a low spring constant. The microcantilever was fabricated with titanium (Ti) as the piezoresistor, a low spring constant polyimide (PI) layer, and a thin silicon oxide (SiO2) layer as the top and bottom passive layers, respectively. Excellent mechanical performances with the spring constant of 0.02128 N/m and the deflection sensitivity of 1.03 × 10−7 nm−1 were obtained. The output voltage fluctuation of a Wheatstone bridge, which consists of four piezoresistive microcantilevers, is less than 3 μV@3 V in a phosphate buffered saline (PBS) environment. A microcantilever aptasensor was then developed through functionalizing the microcantilevers with a ricin aptamer probe, and detections on ricin with concentrations of 10, 20, 50 and 100 ng/mL were successfully realized. A good specificity was also confirmed by using bovine serum albumin (BSA) as a blank control. The experiment results show that the Ti and PI-based microcantilever has great prospects for ultrasensitive biochemical molecule detections with high reliability and specificity.

Design and simulation of RF-MEMS shunt switch for K-band applications

This paper presents the design and simulation of shunt type switch with meanders and perforations. The proposed switch is utilizing silicon nitride (Si3N4) as a dielectric material within the transmission line and the beam is considered as gold (Au), and it offers several benefits in terms of performance such as low spring constant, pull-in voltage, and also good S-parameters. The pull-in voltage is obtained as 4.6 V, the dielectric materials are utilized to improve the capacitance of the switch, which is having is 4.62 fF and 3.94 pF. The Electro-magnetic analysis is done by using the HFSS tool, the return and insertion of the proposed switch are maintained as − 44.69 dB and 0.415 dB at 22 GHz frequency. The isolation is observed at − 40.37 dB at 20 GHz frequency. The proposed device having good results at the 20–22 GHz frequency range. The proposed switch, which operates in the range of 1–25 GHz, gives good results when associated with other devices and is utilizing for K-band and wireless communication systems.

Design of V-shaped cantilevers for enhanced multifrequency AFM measurements.

As the application of atomic force microscopy (AFM) in soft matter characterization has expanded, the use of different types of cantilevers for these studies have also increased. One of the most common types of cantilevers used in soft matter imaging is V-shaped cantilevers due to their low normal spring constant. These types of cantilevers are also suitable for nanomanipulation due to their high lateral spring constants. The combination of low normal spring constant and high lateral spring constants makes V-shaped cantilevers promising candidates for imaging soft matter. Although these cantilevers are widely used in the field, there are no studies on the static and dynamic behavior of V-shaped cantilevers in multifrequency AFM due to their complex geometry. In this work, the static and dynamic properties of V-shaped cantilevers are studied while investigating their performance in multifrequency AFM (specifically bimodal AFM). By modeling the cantilevers based on Timoshenko beam theory, the geometrical dimensions such as length, base width, leg width and thickness are studied. By finding the static properties (mass, spring constants) and dynamic properties (resonance frequencies and quality factors) for different geometrical dimensions, the optimum V-shaped cantilever that can provide the maximum phase contrast in bimodal AFM between gold (Au) and polystyrene (PS) is found. Based on this study, it is found that as the length of the cantilever increases the 2nd eigenmode phase contrast decreases. However, the base width exhibits the opposite relationship. It is also found that the leg width does not have a monotone relationship similar to length and base width. The phase contrast increases for the range of 14 to 32 µm but decreases afterwards. The thickness of a V-shaped cantilever does not play a major role in defining the dynamics of the cantilever compared to other parameters. This work shows that in order to maximize the phase contrast, the ratio of second to first eigenmode frequencies should be minimized and be close to a whole number. Additionally, since V-shaped cantilevers are mostly used for soft matter imaging, lower frequency ratios dictate lower spring constant ratios, which can be advantageous due to lower forces applied to the surface by the tip given a sufficiently high first eigenmode frequency. Finally, two commercially available V-shaped cantilevers are theoretically and experimentally benchmarked with an optimum rectangular cantilever. Two sets of bimodal AFM experiments are carried out on Au-PS and PS-LDPE (polystyrene and low-density polyethylene) samples to verify the simulation results.

Presence of microplastics in benthic macroinvertebrates along the Kenyan coast

Microplastics (MPs) are plastics less than 5 mm in diameter. Their small size renders them invisible to deposit- and filter-feeding fauna, leading to unintentional ingestion. This study investigated the presence of MPs in an oyster (Saccostrea cuccullata) and three species of brachyuran crabs (Tubuca dussumieri, Cranuca inversa and Gelasimus vocans) along the Kenyan coast. Sampling was carried out at eight stations distributed between three sites: Tudor, Port Reitz and Mida creeks, in January and February 2018, during low spring tide. The sample comprised 206 crabs and 70 oysters. Samples were digested using 10% KOH at 60 °C for 24 hours and then passed through 38-µm sieves. Sieved products (<38 µm) were filtered through Whatman filter membranes (0.8 µm) and viewed under a dissecting microscope for MPs. The study identified mainly MP fibres, which were of different colours: red, yellow, black, pink, orange, purple, green, blue and colourless. Colourless fibres were the most prevalent, comprising at least 60% of the total MPs. Mean lengths of MPs fibres of different colours were between 0.1 and 4.2 mm. The mean concentration of MPs (MPs g−1 wet tissue) was 0.65 (SE 0.13) in crabs and 3.36 (SE 0.53) in oysters, and the difference between the two taxa was significant (independent two-sample t-test: t = 5.61, df = 14, p = 0.01). The higher mean concentration in oysters was attributed mainly to their filter-feeding habit. This study exposes MP pollution along the Kenyan coast and its uptake by marine fauna, and thus strengthens the case for better control of plastic wastes in the ocean.

Manufacturing Process beyond Conventional Plasticity Theory: Case Study in Manufacturing Low Spring Index Coil

In the academic world, conventional plasticity theory limits the cold process due to energy inefficiency, material properties and residual stress that may inhibit the quality of a product, and therefore usually not recommended. However, industrial competition pushes that limits against the edge. Knowing the consequences in advance helps reducing the damage that may have been caused by such a violation. This paper shows an example in the form of a case study. A coil spring with a very low spring index that academically suggested to be made using hot process was attempted to be manufactured using cold coiling machine. The case study shows that although it is possible, extra careful and timely handling must be done to successfully manufacture it. A coil with excessive residual stress is shown in this paper. That residual stress alone was capable in damaging the coil during manufacturing. The defect takes place after coiling and before tempering process. A fracture mechanics was used to analyze the failure, which is the splitting due to excessive residual stress. The case study also shows that the problem can be solved by speedy and subsequent stress relieve annealing process.

The influence of soil tillage system on Salsola kali L. emergence during the fallow period within cereal fields

AbstractWith the move towards conservation agriculture, we have seen an increase in weeds such as Salsola kali L., well known as Russian thistle, which are wind spread over fallow land. The emergence of this weed species seemed erratic, perhaps connected to climate conditions and management techniques. In order to shed some light on this issue, we carried out a field experiment over 3 years to monitor Russian thistle density in fallow plots, comparing three tillage systems. This study provides an insight about the limitations of assuming no‐tillage techniques within a cropping system that include fallow in the rotation sequence. Our results show that no‐tillage systems are more vulnerable to S. kali. Low spring rain leads to high S. kali density, especially in no‐tillage plots. High spring rainfall reduced the emergence in all tillage systems because of soil water saturation. Minimum tillage technique served to maintain control over this species even in weather conditions that favoured its emergence in other systems. In order to reduce the need for herbicide in fallow lands under conservation systems, we recommend the implementation of minimum tillage to combat Russian thistle infestation.

Qualitative Analysis of Phytocompounds of Liagora divaricata and Trematocarpus flabellatus

Introduction: Phytocompounds are a powerful chemical group obtained from natural resources that exhibit a range of biological activities. Objective: This study explored the phytocompounds constituents of two species of Rhodophyta, Liagora divaricata and Trematocarpus flabellatus in order to give a preliminary view of qualitative diversity of potentially bioactive compounds. Methods: Approximately 200g of each species were hand-picked at in Chongoene, Mozambique, during a low spring tide. Voucher specimens were identified and stored at the LMU herbarium in the Department of Biological Science, University of Eduardo Mondlane. Samples were cleaned and dried at 50°C for 72 hours before grounding using an electric mixer. Powdered samples were extracted with methanol solvent. Phytocompounds samples were analysed using the GC-MS and identified based in NIST mass spectral library. Results: A total of 42 phytocompounds were identified. The common identities from both seaweeds species include Cholesterol, Desmosterol, Heptadecane, Hexadecanoic acid methyl ester, n-Hexadecanoic acid, Neophytadiene and Phytol. Conclusion: Due to the relevance of these phytocompounds in different industries such as pharmacy, nutrition, agriculture and cosmetic, the identified seaweeds might be good candidates for further research in terms of isolating and validating their activity. Particular attention should focus on Neophytadiene due to its strong bioactive compound in several applications.&#x0D; Keywords: Phytocompounds, Liagora divaricata, Trematocarpus flabellatus, Neophytadiene

Seawater Intrusion on the Arctic Coast (Svalbard): The Concept of Onshore-Permafrost Wedge

Numerous hydrogeological studies on the coastal zone describe the intrusion of sea water inland, salting underground aquifers. The phenomenon is commonly observed in the coasts outside polar areas. However, the impact of sea water has so far not been an object of detailed investigation in a periglacial environment devoid of subsea permafrost. Geophysical measurements at the west coast of the Wedel-Jarlsberg Land in Svalbard indicate that the border between the unfrozen seabed and the frozen ground onshore is not delimited by the shoreline. A zone of coastal unfrozen ground is located under a thin layer of permafrost reaching toward the sea. This state was observed with the use of electrical resistivity tomography under rocky headlands and capes, uplifted marine terraces located at the foot of mountain massifs and valley mouths as well as in the marginal zone of the Werenskiold Glacier. This short article presents the results of such a measurement, supplemented with electromagnetic detection. The measurements are unique in that they were conducted not only on the land surface, but also at the floor of the sea bay during the low water spring tide. The author proposes name structures detected in the coastal zone as a “permafrost wedge”, extending an identification of the permafrost base between the coast and the glaciers of Svalbard. However, in the absence of boreholes that would allow determining the thermal state of the ground in the study sites, the concept is based only on the interpretation of the geophysical imaging. Therefore, further discussion is required on whether the identified contrasts in electrical resistivity indeed result from thermal differences between the rocks or if they only indicate the cryotic state of the ground (saline cryopeg) within the range of seawater intrusion.