Penetration tests are one of important geotechnical insitu tests by which, different soil parameters can be estimated. The advantages of these tests are easiness, high speed, and repeatability. In this research, a penetrometer called as “, Manual dynamic penetrometer (MDP)”,is utilized to perform tests on dry Firoozkuh Sand with three different relative densities. The MDP is similar to other penetrometers used in geotechnical engineering, but the dimension is different which causes to generate more power to penetrate into the soil with deeper layers. The aim of this research is to investigate the effect of cone geometry as well as applied energy on test results. To do so, three different cone diameters and cone apex are considered. In addition, the mass of the hammer is also changed in three different values. The comparison of results indicate that the come apex does not influence the penetration value,however, the cone diameter plays the role. It is also seen that the applied energy has direct relationship with the penetration. Since the mechanism of the cone penetration is similar to that of pile driving, it was also shown that it is possible to estimate the residual internal friction angle of the soil by using empirical formula proposed by Meyerhof.

The Extended dynamic Cone Penetration (EDCP) test supplemented by measurement of torque (EDCP-T) may be used to obtain a direct measurement of unit skin friction (f s) between the cone section and the surrounding soil. The test is performed after completion of the EDCP test.In order to perform the EDCP-T, the EDCP device is rotated after driving the rod and maximum torque is measured using a calibrated torque wrench that is connected to the top of the EDCP. The EDCP-T test results at 3 sites are presented. The results show that the unit skin friction values obtained from the EDCP-T generally correlate well with normalized blows for 30 cm penetration of the EDCP tip (N EDCP(n)). The results may be valuable for preliminary estimation of unit skin friction of the driven piles.

Soil compaction is an important aspect of agriculture and different methods are available to measure this parameter. One method is called the cone index; measuring the force required per unit area for penetration of a standard steel cone into the ground. Cone penetrometers are used for cone index measurement. In this study, a tractor mounted, hydraulically-operated penetrometer was designed, built and evaluated. The penetrometer consisted of a frame, hydraulic driving unit, force transducer, depth measuring unit and data acquisition system. The entire penetrometer unit was mounted on the frame and held in place by the three-point hitch on a category III tractor. The hydraulic driving unit provided a constant penetration rate of 3 cm/s, in accordance with the ASAE S313.3 standard. A cantilever beam strain-gauge load cell measured the penetration force applied to the cone shaft and a photodiode sensor measured the penetration depth. A microcontroller-based data acquisition system was designed and developed to record and save the penetration data. Evaluations were conducted by comparing the data of the tractor- mounted penetrometer and that of a commercial hand-pushed penetrometer (Eijkelkamp). Analysis found no significant difference at the 95% confidence level. The penetrometer performance was found to be reliable and the unit's mechanical and electronic parts worked without malfunction.

The blunt tipped “Perth Sand penetrometer” is used extensively in Australia for characterization of silica sand sites prior to the construction of light weight domestic structures.The hand operated device, which can be readily deployed in fine granular soils at depths up to 5 m, is routinely and successfully used to infer in situ density and internal friction angles in extensive coastal sand deposits. Some calibration charts are presented for a light weight dynamic penetrometer device. The charts presented here are based on the results of 18 calibration chamber tests, performed in a specially constructed chamber, 1m high and 1m in diameter. All tests were performed on silica sand samples were consistently prepared to 3 densities using the sand raining or pluviation technique. The prepared samples were pressurized during testing to simulate overburden effects due to burial at depths up to 5m. Particular account is taken of the effects of rod friction.

For a determination of soil characteristics one should have access to instruments that can measure these characteristics, including: soil penetration resistance with high accuracy. One of the accurate instruments commonly employed in soil penetration determinations is cone penetrometer. This apparatus, by measuring soil cone index at different soil depths can provide useful about information about the soil. In this research a digital cone penetrometer was designed and fabricated. For a later evaluation of the apparatus, tests were carried out on grassland with three levels of moisture content (13%, 34% and 86%). The accuracy of the displacement and force measurement setups were recorded as 0.01 mm and 1.96 N, respectively. Based on the results of the experiments, with an increase in grassland (muskeg) moisture content, soil penetration resistance, increased, such that with an increase of a low level of penetration force, penetration increased greatly. Value of critical pressure at a level of moisture content of 13% was more than those at the other levels of moisture contents.

Due to the lack of measurements in many regions, wave characteristics are estimated using different methods. Wave climate hindcasting/forecasting is mostly conducted by numerical models or empirical methods. Until now, different empirical methods have been developed for wave hindcasting. However, with the development of high speed processors, several sophisticated numerical models have been developed for wave prediction. These models are mostly phase-averaged spectral wave models developed in three generations. In the last two decades, third generation wave models have been used widely in academic and practical projects. In this regard, Port and Maritime Organization has produced his own model, PMO dynamic. This model has been developed as a part of first three phases of Monitoring and Modeling of Study of Iranian Coasts project. PMO dynamic package is a software available for engineering purposes. It has several modules that have been developed for different objectives. Wave model is the module which is used for the generation and transformation of wind waves in coastal areas. In this paper, in order to test the PMO dynamic model capabilities, it has been applied for the prediction of wave parameters in Bushehr Bay and the results have been compared with MIKE21 SW model and measured data.

Background: In intertrochanteric fractures، dynamic hip screw (DHS) is the most frequently used tool، but several studies did not give good results for this device in reverse-oblique and transverse fractures. Current study aimed to compare fixation results of reverse-oblique intertrochanteric and short-segment subtrochanteric fractures using dynamic condylar screw (DCS) and DHS in patients referred to Alzahra and Kashani Hospitals in Isfahan, Iran.Methods: In a cross-sectional study، medical files of the patients referred to emergency units of the two hospitals who were diagnosed with intertrochanteric or subtrochanteric fractures and underwent DHS or DCS surgery more than 6 months before were assessed; they were invited for follow-up visit and examination. Written consent forms were taken from all the patients upon their entry; and they were examined in terms of complications including nonunion and failure of device and level of fracture improvement. These cases were evaluated by simple radiography ,too. Results obtained from examination of patients in addition to demographic information were recorded in the data collection form for each patient.Findings: Perfect union was observed in 14 (of 25) patients in DHS group and 21 (of 25) patients in DCS group (56% vs. 84%) six months after the surgery. Bone union was significantly better in DCS group (P=0.031). In addition, six months after the surgery, the devices used in 14 people in DHS group and 24 people in DCS group were fixed and the difference between the two groups was significant (P=0.001). 14 and 24 patients had total recovery in DHS and DCS groups، respectively (20% vs. 44%) with a significant difference (P=0.020).Conclusion: Considering obtained results, it can be concluded that using DCS is recommended over DHS due to severity of pain, bone union and fixation of the device.

IntroductionPrecision agriculture is a modern approach to farming that ensures the crops and soil receive exactly what they need for optimum health and productivity. Precision agriculture offers the potential to automate and simplify the collection and analysis of information. It allows management decisions to be quickly made and implemented in small areas of larger fields. Measuring acoustic signals with a cone penetrometer is an advanced and inexpensive method that provides a lot of information about the soil within the shortest amount of time and with the lowest cost. The texture of the soil determines the percentage of the constituents of the mineral part of the soil such as sand, silt, and clay.In this study, an acoustic penetrometer is developed to provide an accurate method for determining the soil texture. This system uses a microphone to record the sound produced by the cone-soil contact and correlates this data with the soil texture.Materials and MethodsAn acoustic cone penetrometer (ACPT) was designed to determine if there is a relationship between the sound produced at the cone-soil contact and soil particle size. Three types of cones with angles of 30, 45, and 60 degrees, diameter of 20.27 mm, and rod length of 300 mm according to ASAE standard S313.3 FEB1999ED (R2013) were used to determine the relationship between sound and soil texture and to choose the best angle. A microphone (20-20,000 Hz) suitable for fast dynamic responses was used to record the audio signals produced from the soil. Audio signals were stored online through the oscilloscope section of Matlab software. To create the controlled vertical movement of the cones, a mechanical mechanism with electronic controllers was designed. This mechanism can be connected to the rails of the soilbin available in Urmia University, Iran, and is made of a 5 hp electric motor with a gearbox, an inverter for controlling the rotational speed of the electric motor, and a digital ruler for recording vertical movement. Soil samples were tested in 19-liter bins.Acoustic signals received from the microphone were processed in the time-frequency domain using wavelet transform. In this research, Daubechi function type 3 is used to analyze acoustic signals. It is not possible to use the processed acoustic signals directly for statistical analysis. Therefore, the relevant features should be extracted from them.  From the 30 features of time domain signals, the most effective and main features include: SUM, Max, RMS, average, Var, kurtosis, and Moment4. They were ranked using the feature selection section of WEKA 3.9.2 software to avoid increasing the volume of calculations, increase processing speed, and reduce errors. The characteristic vector of the sub-signals of several different soil samples was analyzed to distinguish the soil type and constituents namely sand, silt, and clay.Results and DiscussionThe best type of cone was selected using WEKA software. The number of features in the d1 sub-signals was higher for the 45-degree cone, and it can be concluded that with this cone, the soil type can be better recognized.The average values of characteristics in clay, loam, and sand had an increasing trend, respectively, and were statistically significant with a probability of 1% and 5%.Acoustic signals for clay soil, which has a heavy texture and small particles, have minimum amplitude, and for loamy and sandy soils, they were observed as medium and maximum, respectively. This will cause the values of the selected features of clay soil to be low, and as a result, the average values, variance, and standard deviation are also low. They would be higher for loamy and sandy soil which have larger particles. It can be deduced that, as the size of the soil particles increases, the particles hitting the cone wall would become heavier and would affect the frequency and amplitude of the signal. This will result in the increase of signal amplitude values and, the sum, max, and mean values as well.ConclusionAmong the sub-signals, the maximum effect of soil texture type changes was related to d1 sub-signals for the 45̊ cone, and these signals had more potential to identify the soil texture type. Among the features, the sum, average, VAR, and RMS were significant at 1% probability levels. Therefore, these features have more potential to detect the type of soil texture in the mentioned sub-signal. Additionally, the effect of soil texture change on Moment and Kurtosis characteristics was significant at 5% probability levels.