function [dxdt] = odesolver_uniformconcentration_new(t,x)

global T_g_0 C1 C2 eps_ref R_g gamma  C_0 c_0 R_0 b_0 x_mesh counter pg_0 pa pressure_vec a_dot_vec ...
    counter_smooth rho_L t_end temp_up temp_low c_vec  eta_g tau t_vec...
    rho_0 M_w rho_vec temp_vec tg_vec ...
    v Q eps_dot_0 E_R  eps_dot_R alpha_R n sigma_plastic_vec stress_vec sigma_rubber  mechanism_vec K_H eos_index KH_index ...
    thickness_vec thickness_check t_min ductility_check T_Tg_vec T_g_0 stree_profile_vec f_int_vec 


% update counter and time vector
counter = counter + 1;
t_vec(counter) = t;
t % to show time development during simulations

b_3 = (x(1)^3-R_0^3+b_0^3); 
temp = temp_function_exp(t,temp_low,temp_up,t_end,tau); % define temperature profile 

if counter == 1
    p = pg_0;
    rho = rho_0; 
    c = c_0;
else
    
% calculate pressure and density of gas     
p = ((b_0^3-R_0^3)*C_0+R_0^3*pg_0/(R_g*temp_low))/(x(1)^3/(R_g*temp) + (b_3 - x(1)^3)*K_H); % pressure by gas mol conservation for given a and constant  KH
rho = p/(R_g*temp)*M_w; 
c = K_H*p; 
end

tg = tg_function(T_g_0,c,rho_L);
a = x(1); 

[fun] = @(a_dot_var) function_root_adot(a_dot_var,a,p,temp,tg);    
if counter == 1 
   a_dot_0 = 0;
else 
    a_dot_0 = a_dot_vec(counter-1);
end

a_dot = fzero(fun,a_dot_0);

a_dot_vec(counter) = a_dot;
dxdt = [a_dot];

    
pressure_vec(counter) = p;
temp_vec(counter) = temp;   
tg_vec(counter) = tg;


end