---

---

A research on reference assignment points to two types of discourse-linked and non-discourse-linked referential status. To explain that whether or not the antecedent information previously existed in the discourse, this paper, by presenting testimonies and samples from the Persian language as well as using the Syntax-Discourse Model tries to determine that the reflexive and personal pronouns of Persian in some cases are discourse-linked. First, the paper introduces discourse-linked and non-discourse-linked referential status. Then, by comparing the Syntax-Discourse Model and Chomsky’s Binding Theory, the paper exemplifies cases to show that the Binding Theory not fruitful, at all, in explaining them  and hence, take up the principles of Syntax-Discourse Model to explained and proved them

---

The natural and bioactive compounds from marine animals can be used as functional compositions for healthcare. Collagen and gelatin of marine animals could be having pharmacological and cosmetic applications. In the present study collagen was extracted from the body wall of sea cucumber (S.horrens) collected from Chahbahar Bay and its Amino acid composition was investigated. Also, gelatin from this collagen was extracted according to acidic hydrolyzed method and the functional properties were studied. The type of purified collagen was identified by the SDS-PAGE method. The results indicated the extracted collagen was the type I, because it had a α₁ chain by the molecular weight of 125 KDa and a heavy band of β chain with the molecular weight of 250 KDa. The collagen contained high amount of Imino Acids and the glycine was the dominant Amino acid. The melting and gelling point of the Gelatin was 30⁰C and 5⁰C, respectively. The viscosity of the gelatin was 2.065 cp, lower than other fish species and mammals.                           

---

a compact size and lightweight planar ultra-wideband (UWB) antenna with an omnidirectional radiation pattern and a stable gain in the frequency range 3.1-10.6 GHz is proposed and investigated. The antenna consists of an elliptical shaped slot which is fed by a 50-Ω microstrip line that is beveled and has fork-shaped is designed. Attaching two inverted U-shape strips at the upper part of the slot, two additional bands are realized covering GPS, upper part of GSM (1770–1840 MHz), and Bluetooth (2385–2490 MHz) bands. The calculated return loss, omni-directional radiation pattern, and peak gain are in good agreement with the measurement results. The antenna can provide high-performance wireless communications over different frequency bands. This structure has a compact size (27×24 mm²), is lightweight, and can be easily fabricated.    According, the proposed antenna is expected and normal to be a good candidate in various applications in portable and lightweight communication system.
 

---

In this paper, we investigate the effect of nano-CaCO3 on water absorption and tribological properties of polyamide-6. To this end, nanocomposites based on polyamide-6 blend, containing 1 to 5 phr of nano-CaCO3, and 1 phr of maleated polyamide (PA-g-MAH) as compatibilizer, are prepared via melt compounding followed by injection molding. The wear testing of each of the prototypes is carried out under identical conditions. Then, the morphology is studied using scanning electron microscopy. The addition of nano-CaCO3 particles with compatibilizer increases the wear resistance and reduces the water absorption. The results of experiments indicate that minimum wear rate is achieved by adding 1 phr of nano-CaCO3 with compatibilizer which is nearly 4 times less than pure PA6. Furthermore, the presence of nano-CaCO3 together with PA-g-MAH lowers the amount of water absorption as high as 32% wt in compare to pure PA6. In addition to these, this fact is also emerged that effect of compatibilizer is prominent on uniform distribution of the nano-CaCO3 particles among polyamide matrix that it leads to improve the tribological properties of the nanocomposite prototypes in the wear test.

---

Ultrasonic Phased Arrays are an emerging technology in nondestructive testing and evaluation. Some important factors affecting on the performance of these probes include, positioning elements in probe, number of elements, distance between two elements, elements length, and time delays to excite probe elements. The type of linear phased array probes is a prevailing type in which elements placed side by side and longitudinally. In this paper based on analyzing the existent laws in design and performance of the phased array probes related to the propagation of ultrasonic waves, an improved dimensional design for ultrasonic linear phased array probes, as well as improvement of the sequence of time delays to excite the probe elements are done. In order to evaluate the performance of the probe with improved design in comparison with a similar ordinary probe, an ultrasonic phased array test is simulated using FEM-based ABAQUS software. By numerical simulations, the performance of the probe with improved design versus the ordinary probe for propagating the guided waves in a thin square aluminum plate is compared. In first part, the attenuation coefficient of the received signals of reflected wave is evaluated, and in second part, the performance of the probes for radial scanning is compared. Results of both simulations confirm that the performance of the probe with improved design is much better than the similar ordinary one. Specially, the probe with improved design propagates the ultrasonic waves with the maximum head wave energy, and steers them with higher accuracy towards a determined direction.

---

Locomotion regulation of a robot according to path conditions is one of the main interests in the robotics, because it enables the robot to move in unknown environments. This can be realized using inspiration from the human and animals' bio-mechanism in generating various motion patterns called central pattern generator (CPG). These motion patterns are called “gaits” and changing between the motion patterns is called “gait transition”. Many models have been proposed to model CPGs and used for trajectory generating of various mobile robots. In this paper, a type of CPG network called 4-cell CPG model is studied to generate the rhythmic signals of the ankle joints in a bipedal locomotion gaits. This model is composed of four coupled identical cells whose internal dynamics is described by the Morris-Lecar nonlinear differential equations and the couplings between the cells follow the diffusive type. The generation of various locomotion gaits depends on the adjustment of the phase differences between rhythmic signals produced by the cells. The phase differences, in-turn, are obtained via properly adjusting the coupling weights between the cells. Here, we exploit a non-dominated sorting genetic algorithm (NSGA-II) to find the best set of coupling weights for maximally approaching the desired phase differences of the primary bipedal gaits of walk, run, two-legged jump, and two-legged hop. Also, some secondary bipedal gaits, especially one that called “hesitation walkˮ, are obtained by symmetry breaking bifurcations of the primary gaits. The “hesitation walkˮ has already predicted in [28], however the authers could not generate it.

---

One of the basic functions of input-output analysis is to identify the economic structure of regions and countries. This research seeks to identify the key sectors of Iran's provinces and to compare them with national key sectors. The data is extracted from the national input-output table and regional accounts of the Statistical Center of Iran in 2011. The results show that based on the "total gross backward and forward linkages" criterion, there are 17 and 20 key sectors, respectively, with and without considering the "dispersion of the linkages", at national level. With same criterion, every province has at least one and two key sectors, respectively. However, some key sectors of provinces are not listed as national key sectors, and are not included in the central planning. On the contrary, a number of national key sectors are not categorized as key sectors in the provincial level. In addition, due to the larger usage of national resources in key sectors, the provinces with more common key sectors with national economy have higher GDP per capita. Thus, it seems due to inconsistency between some regional economic structure with national one, considering the provincial key sectors in national economic planning leads to optimal use of national resources through increasing the GDP per capita and decreasing the interregional disparities.

---

The use of medicinal plants in food has a long history. Flaxseed oil and eucalyptus essential oil are highly regarded due to their biological properties. In this research, the aim is to investigate the antimicrobial properties of zein nanofibers containing flaxseed oil and eucalyptus essential oil to control staphylococcus aureus and escherichia coli bacteria in a laboratory environment. For this purpose, flaxseed oil mixed with eucalyptus essential oil in zein solution. Then, it was converted into nanofibers using an electrospinning machine. In order to study the characteristics and antimicrobial properties of the nanofibers, tests including scanning electron microscopy (SEM), fiber diameter determination with Image J software, atomic force microscopy (AFM), X-ray diffraction (XRD), thermal gravimetric analysis (TGA) were performed. Investigation of antimicrobial properties of produced nanofibers by disk diffusion method were performed. The SEM results showed that the morphology of the electrospun fibers was uniform and free of beads. AFM images represented three-dimensional and tubular images of fibers obtained from electrospinning zein/flaxseed oil/eucalyptus essential oil. The X-ray diffraction pattern showed an increase in the crystallinity intensity of the treatments compared to the control sample. Based on thermal analysis results, eucalyptus and flaxseed oil increased the thermal stability of zein nanofibers. The results showed that the addition of flaxseed oil to eucalyptus essential oil strengthened the antimicrobial properties of nanofibers. According to the results of the present research, the zein/flaxseed oil/eucalyptus essential oil fibers can be used as natural antimicrobials.
 

---

To prevent gasoline smuggling to abroad and its excessive consumption in the country, the price of gasoline increased and gasoline was quoted in 2019. This policy has affected the consumption expenditures of different income groups of households. To compensate the expenditures increment, the government pays subsidies to some income groups of households. This paper investigates the effects of this policy on the consumption expenditures of different income deciles in urban and rural areas and compares them with gasoline subsidies. To this end, a developed version of implicit subsidy elimination model is employed. The input-output table of Iran for the year 2016 is used as database of the research. The results of the research indicate that the subsidy of the government will cover the consumption expenditure increment due to its gasoline price policy for all target income groups. However, this policy fails to compensate the increment of the consumption expenditure in the case in which the labour force and capital owners adjust their endowments and the exchange rate is changed with respect to domestic price inflation. 

---

---

Covid-19 is a highly infectious viral disease caused by SARS-CoV-2, which has spread worldwide since its emersion in December 2019, causing an unprecedented pandemic. Currently, it has no targeted vaccines or treatments, and effective treatment options are very limited. It is important to identify drugs that effectively inhibit a specific target of the SARS coronavirus. This is the third deadly outbreak of coronaviruses in human society which has put pressure on the global health care system and affected the global economy a well. However, the treatment options of Covid-19 are still very limited. The development of drugs that target and inhibit essential proteins in the viral life cycle is a practical approach to overcoming this hard situation. The main protease, a cysteine protease, is an attractive target for antiviral drugs against SARS-CoV-2 and other coronavirus infections due to its essential role in viral replication and transcription. To quickly detect effective compounds for clinical use, programs such as molecular docking drug design and virtual screening of pre-designed drugs to identify new compounds and drugs that target the main protease of the COVID-19 are performed. Combining these structural studies, virtual screening, and experimental screen, several therapeutic candidates such as repurposed drugs and ab initio designed drugs have been proposed. In this review study, suggestions for inhibitors and possible potentially effective drugs against the main protease of SARS-CoV-2 were discussed. This study paves the way for advanced experimental research to evaluate the pharmacological potential of these compounds for the treatment of Covid-19.

---

Aim and Introduction
In the conventional Input-Output model, all final demand components including household consumption, government expenditures, capital accumulation and exports are considered as exogenous variables. The basic limitation of the open Input-Output model is ignorance the relationship between the production sector and the household. In this way, if there is an increase in demand for the products of some industries, such an event will directly lead to an increase in the production level of these industries in the first place. On the other hand, the increase in production in turn leads to an increase in the level of production in related industries through previous connections. The increase in income resulting from higher levels of household economic activities leads to an increase in household consumption and as a result stimulates more activities in the production sector. Based on this, the production sector and the households are related to each other through the income-consumption relationship.In order to estimate the income-consumption relationship, household consumption should be included as an endogenous variable in the Input-Output model, while in the conventional (open) Input-Output model, household consumption is considered as an exogenous variable. To solve this limitation, Miyazawa (1976) presented a new Input-Output model in which he considered household consumption as an endogenous variable. Miyazawa's model is known in the relevant literature as a semi-closed Input-Output model with endogenous consumption. Despite this, Miyazawa's model, similar to Keynes' consumption theory, considers household consumption solely as a function of current income, while according to other theories of consumption behavior, household consumption depends on other factors such as past consumption levels and income. It also depends on the expectation. Accordingly, in this research, the semi-closed Input-Output model with semi-endogenous consumption, introduced by Chen et al (2016), was used because this new model adapts the Input-Output model to other consumption theories and corrects the failure of the previous model. In this framework, household consumption is divided into two endogenous and exogenous parts, so that the endogenous component is influenced by current income and the exogenous component is influenced by other factors affecting consumption. In fact, it is only endogenous consumption that enters the mediation matrix.
Methodology
In this research, the results of the new semi-closed Input-Output model with semi-endogenous consumption (Chen et al (2016) model) and the semi-closed Input-Output model with completely endogenous consumption (Miyazawa (1976) model) were compared. In this regard, first, endogenous consumption coefficients for 12 product groups were estimated using the Kalman filter model, and then, the estimated endogenous consumption coefficient of each category of goods was compared to the endogenous consumption coefficient of the data sections by means of the interface matrix. The receipt was converted.
In order to compare the performance of the two models of Miyazawa (1976) and the model of Chen et al (2016), the effect of government capital formation on the value added of different sectors was evaluated using the two mentioned models.
Findings
Failure to consider other factors affecting consumption will lead to upward deviation in GDP estimation. In this way, it can be concluded that the semi-endogenous model solves the insufficiency of the completely endogenous model and its results are closer to reality.
Discussion and Conclusion

the gross domestic product was obtained based on fully endogenous and semi-endogenous models (9601201) and (9329172), respectively. These findings show that Miyazawa model considers all household consumption as a function of current income, and also due to the lack of consideration of other factors affecting consumption such as expected income, consumption level. Also, in Chen et al.'s model, the calculated added value is smaller compared to Miyazawa's model, because by analyzing and separating exogenous consumption from total consumption, only endogenous consumption entered the table of intermediary exchanges.
 

---

---

A breach of a contractual obligation can not only cause damage to an obligor but also cause damage to third parties. The damage resulting from breach of contractual obligations is mainly material or moral for which a contracting party can claim within the framework of contractual civil liability and a third party can claim in the realm of non-contractual civil liability. However, today there are also other types called pure economic losses have no material origin (property or body) and may cause by a third party or contracting party due to intentional or negligent breach of a contractual obligation by the obligor. In this type of loss, the liability of obligor toward obligee is less questionable but the liability of the obligor to a third party for these damages is discussed in legal regimes. In British Law, the liability of the contractor against a third party is exceptional while in Iranian law there is no general rule allowing a third party to sue contractual party for a breach of contract, however, the general duty of the contractual obligor to take care of the third party in the direction of the principle which can be invoked in the contract, and also the rules of civil liability, protect the legal rights of the injured party. It seems that despite the lack of an explicit text, its design is not far from the mind, this is what will be comparatively expressed in this article based on an inspiration of the provisions of British law.